Dictionary deinflections (#503)

* wip

* wip

* fix v3

* wip

* fix tests

* fix maxitems

* hide deinflection definitions

* fix anki template

* undo unnecessary change

* delete console.log

* refactor

* add set false to handlebars

* lint

* fix tests

* fix comments

* fix

* use Map in areArraysEqualIgnoreOrder

* move inflection source icons to css

* lint

* improve naming

* fix tests

* add test

* typescript

* use for of

* wip

* comments

* anki template upgrade

* update descriptions

16 files changed, 411 insertions, 67 deletions

diff --git a/ext/css/display.css b/ext/css/display.css
index 49aeaaa5..e0b7ab6d 100644
--- a/ext/css/display.css
+++ b/ext/css/display.css
@@ -809,17 +809,39 @@ button.action-button:active {
 
 
 /* Inflections */
-.inflection-list {
-    display: inline-block;
+.inflection-rule-chains {
+    padding-inline-start: 0;
+    list-style-type: none;
+}
+.inflection-rule-chain {
     color: var(--reason-text-color);
 }
-.inflection-list:empty {
+.inflection-rule-chain:empty {
     display: none;
 }
-.inflection-list>.inflection+.inflection-separator+.inflection::before {
+.inflection-rule-chain>.inflection+.inflection-separator+.inflection::before {
     content: var(--inflection-separator);
     padding: 0 0.25em;
 }
+.inflection-source-icon {
+    display: inline-block;
+    white-space: nowrap;
+    text-align: center;
+    width: 1.4em;
+    margin-right: 0.2em;
+}
+.inflection-source-icon[data-inflection-source='dictionary']::after {
+    content: '📖';
+}
+.inflection-source-icon[data-inflection-source='algorithm']::after {
+    content: '🧩';
+}
+.inflection-source-icon[data-inflection-source='both'] {
+    width: 2.8em;
+}
+.inflection-source-icon[data-inflection-source='both']::after {
+    content: '🧩📖';
+}
 
 
 /* Headwords */
diff --git a/ext/data/schemas/dictionary-term-bank-v3-schema.json b/ext/data/schemas/dictionary-term-bank-v3-schema.json
index 8243f2a7..066229c3 100644
--- a/ext/data/schemas/dictionary-term-bank-v3-schema.json
+++ b/ext/data/schemas/dictionary-term-bank-v3-schema.json
@@ -400,7 +400,7 @@
             },
             {
                 "type": "string",
-                "description": "String of space-separated rule identifiers for the definition which is used to validate delinflection. Valid rule identifiers are: v1: ichidan verb; v5: godan verb; vs: suru verb; vk: kuru verb; adj-i: i-adjective. An empty string corresponds to words which aren't inflected, such as nouns."
+                "description": "String of space-separated rule identifiers for the definition which is used to validate deinflection. An empty string should be used for words which aren't inflected."
             },
             {
                 "type": "number",
@@ -535,6 +535,24 @@
                                     }
                                 }
                             ]
+                        },
+                        {
+                            "type": "array",
+                            "description": "Deinflection of the term to an uninflected term.",
+                            "items": [
+                                {
+                                    "type": "string",
+                                    "description": "The uninflected term."
+                                },
+                                {
+                                    "type": "array",
+                                    "description": "A chain of inflection rules that produced the inflected term",
+                                    "items": {
+                                        "type": "string",
+                                        "description": "A single inflection rule."
+                                    }
+                                }
+                            ]
                         }
                     ]
                 }
diff --git a/ext/data/schemas/options-schema.json b/ext/data/schemas/options-schema.json
index 8cf00400..24f3a6b0 100644
--- a/ext/data/schemas/options-schema.json
+++ b/ext/data/schemas/options-schema.json
@@ -823,7 +823,8 @@
                                         "enabled",
                                         "allowSecondarySearches",
                                         "definitionsCollapsible",
-                                        "partsOfSpeechFilter"
+                                        "partsOfSpeechFilter",
+                                        "useDeinflections"
                                     ],
                                     "properties": {
                                         "name": {
@@ -850,6 +851,10 @@
                                         "partsOfSpeechFilter": {
                                             "type": "boolean",
                                             "default": true
+                                        },
+                                        "useDeinflections": {
+                                            "type": "boolean",
+                                            "default": true
                                         }
                                     }
                                 }
diff --git a/ext/data/templates/anki-field-templates-upgrade-v24.handlebars b/ext/data/templates/anki-field-templates-upgrade-v24.handlebars
new file mode 100644
index 00000000..2288737c
--- /dev/null
+++ b/ext/data/templates/anki-field-templates-upgrade-v24.handlebars
@@ -0,0 +1,52 @@
+{{#*inline "phonetic-transcriptions"}}
+    {{~#if (op ">" definition.phoneticTranscriptions.length 0)~}}
+        <ul>
+            {{~#each definition.phoneticTranscriptions~}}
+                {{~#each phoneticTranscriptions~}}
+                    <li>
+                        {{~set "any" false~}}   
+                        {{~#each tags~}}
+                            {{~#if (get "any")}}, {{else}}<i>({{/if~}}
+                            {{name}}
+                            {{~set "any" true~}}
+                        {{~/each~}}
+                        {{~#if (get "any")}})</i> {{/if~}}
+                        {{ipa~}}
+                    </li>
+                {{~/each~}}
+            {{~/each~}}
+        </ul>
+    {{~/if~}}
+{{/inline}}
+
+{{<<<<<<<}}
+{{#*inline "conjugation"}}
+    {{~#if (op ">" definition.inflectionRuleChainCandidates.length 0)~}}
+        {{~set "multiple" false~}}
+        {{~#if (op ">" definition.inflectionRuleChainCandidates.length 1)~}}
+            {{~set "multiple" true~}}
+        {{~/if~}}
+        {{~#if (get "multiple")~}}<ul>{{/if~}}
+            {{~#each definition.inflectionRuleChainCandidates~}}
+                {{~#if (op ">" inflectionRules.length 0)~}}
+                    {{~#if (get "multiple")~}}<li>{{/if~}}
+                    {{~#each inflectionRules~}}
+                        {{~#if (op ">" @index 0)}} « {{/if~}}
+                        {{.}}
+                    {{~/each~}}
+                    {{~#if (get "multiple")~}}</li>{{/if~}}
+                {{~/if~}}
+            {{~/each~}}
+        {{~#if (get "multiple")~}}</ul>{{/if~}}
+    {{~/if~}}
+{{/inline}}
+{{=======}}
+{{#*inline "conjugation"}}
+    {{~#if definition.reasons~}}
+        {{~#each definition.reasons~}}
+            {{~#if (op ">" @index 0)}} « {{/if~}}
+            {{.}}
+        {{~/each~}}
+    {{~/if~}}
+{{/inline}}
+{{>>>>>>>>}}
diff --git a/ext/data/templates/default-anki-field-templates.handlebars b/ext/data/templates/default-anki-field-templates.handlebars
index f23b9d0b..818677ce 100644
--- a/ext/data/templates/default-anki-field-templates.handlebars
+++ b/ext/data/templates/default-anki-field-templates.handlebars
@@ -261,11 +261,23 @@
 {{/inline}}
 
 {{#*inline "conjugation"}}
-    {{~#if definition.reasons~}}
-        {{~#each definition.reasons~}}
-            {{~#if (op ">" @index 0)}} « {{/if~}}
-            {{.}}
-        {{~/each~}}
+    {{~#if (op ">" definition.inflectionRuleChainCandidates.length 0)~}}
+        {{~set "multiple" false~}}
+        {{~#if (op ">" definition.inflectionRuleChainCandidates.length 1)~}}
+            {{~set "multiple" true~}}
+        {{~/if~}}
+        {{~#if (get "multiple")~}}<ul>{{/if~}}
+            {{~#each definition.inflectionRuleChainCandidates~}}
+                {{~#if (op ">" inflectionRules.length 0)~}}
+                    {{~#if (get "multiple")~}}<li>{{/if~}}
+                    {{~#each inflectionRules~}}
+                        {{~#if (op ">" @index 0)}} « {{/if~}}
+                        {{.}}
+                    {{~/each~}}
+                    {{~#if (get "multiple")~}}</li>{{/if~}}
+                {{~/if~}}
+            {{~/each~}}
+        {{~#if (get "multiple")~}}</ul>{{/if~}}
     {{~/if~}}
 {{/inline}}
 
diff --git a/ext/display-templates.html b/ext/display-templates.html
index ed0037bb..a50cea3b 100644
--- a/ext/display-templates.html
+++ b/ext/display-templates.html
@@ -32,7 +32,7 @@
         <div class="headword-list"></div>
         <div class="headword-list-details">
             <div class="headword-list-tag-list tag-list"></div>
-            <div class="inflection-list"></div>
+            <ul class="inflection-rule-chains"></ul>
         </div>
     </div>
     <div class="entry-body">
@@ -77,6 +77,7 @@
 <template id="definition-disambiguation-template"><span class="definition-disambiguation"></span></template>
 <template id="gloss-item-template"><li class="gloss-item click-scannable"><span class="gloss-separator"> </span><span class="gloss-content"></span></li></template>
 <template id="gloss-item-image-description-template"> <span class="gloss-image-description"></span></template>
+<template id="inflection-rule-chain-template"><li class="inflection-rule-chain"></li></template>
 <template id="inflection-template"><span class="inflection"></span><span class="inflection-separator"> </span></template>
 
 <!-- Frequency templates -->
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index a5a42272..bc4f222f 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -2428,7 +2428,8 @@ export class Backend {
                 index: enabledDictionaryMap.size,
                 priority: 0,
                 allowSecondarySearches: false,
-                partsOfSpeechFilter: true
+                partsOfSpeechFilter: true,
+                useDeinflections: true
             });
             excludeDictionaryDefinitions = new Set();
             excludeDictionaryDefinitions.add(mainDictionary);
@@ -2474,12 +2475,13 @@ export class Backend {
         const enabledDictionaryMap = new Map();
         for (const dictionary of options.dictionaries) {
             if (!dictionary.enabled) { continue; }
-            const {name, priority, allowSecondarySearches, partsOfSpeechFilter} = dictionary;
+            const {name, priority, allowSecondarySearches, partsOfSpeechFilter, useDeinflections} = dictionary;
             enabledDictionaryMap.set(name, {
                 index: enabledDictionaryMap.size,
                 priority,
                 allowSecondarySearches,
-                partsOfSpeechFilter
+                partsOfSpeechFilter,
+                useDeinflections
             });
         }
         return enabledDictionaryMap;
diff --git a/ext/js/data/options-util.js b/ext/js/data/options-util.js
index c93e261d..0aabed6f 100644
--- a/ext/js/data/options-util.js
+++ b/ext/js/data/options-util.js
@@ -556,7 +556,8 @@ export class OptionsUtil {
             this._updateVersion20,
             this._updateVersion21,
             this._updateVersion22,
-            this._updateVersion23
+            this._updateVersion23,
+            this._updateVersion24
         ];
         if (typeof targetVersion === 'number' && targetVersion < result.length) {
             result.splice(targetVersion);
@@ -1156,6 +1157,20 @@ export class OptionsUtil {
     }
 
     /**
+     * - Added dictionaries[].useDeinflections.
+     * @type {import('options-util').UpdateFunction}
+     */
+    async _updateVersion24(options) {
+        await this._applyAnkiFieldTemplatesPatch(options, '/data/templates/anki-field-templates-upgrade-v24.handlebars');
+
+        for (const {options: profileOptions} of options.profiles) {
+            for (const dictionary of profileOptions.dictionaries) {
+                dictionary.useDeinflections = true;
+            }
+        }
+    }
+
+    /**
      * @param {string} url
      * @returns {Promise<chrome.tabs.Tab>}
      */
diff --git a/ext/js/data/sandbox/anki-note-data-creator.js b/ext/js/data/sandbox/anki-note-data-creator.js
index c0a11869..77d6e357 100644
--- a/ext/js/data/sandbox/anki-note-data-creator.js
+++ b/ext/js/data/sandbox/anki-note-data-creator.js
@@ -376,7 +376,7 @@ export class AnkiNoteDataCreator {
             case 'merge': type = 'termMerged'; break;
         }
 
-        const {inflections, score, dictionaryIndex, dictionaryPriority, sourceTermExactMatchCount, definitions} = dictionaryEntry;
+        const {inflectionRuleChainCandidates, score, dictionaryIndex, dictionaryPriority, sourceTermExactMatchCount, definitions} = dictionaryEntry;
 
         let {url} = context;
         if (typeof url !== 'string') { url = ''; }
@@ -401,7 +401,7 @@ export class AnkiNoteDataCreator {
             source: (primarySource !== null ? primarySource.transformedText : null),
             rawSource: (primarySource !== null ? primarySource.originalText : null),
             sourceTerm: (type !== 'termMerged' ? (primarySource !== null ? primarySource.deinflectedText : null) : void 0),
-            reasons: inflections,
+            inflectionRuleChainCandidates,
             score,
             isPrimary: (type === 'term' ? dictionaryEntry.isPrimary : void 0),
             get sequence() { return self.getCachedValue(sequence); },
diff --git a/ext/js/dictionary/dictionary-importer.js b/ext/js/dictionary/dictionary-importer.js
index bfd7a8b2..8df7860e 100644
--- a/ext/js/dictionary/dictionary-importer.js
+++ b/ext/js/dictionary/dictionary-importer.js
@@ -160,7 +160,7 @@ export class DictionaryImporter {
             const glossaryList = entry.glossary;
             for (let j = 0, jj = glossaryList.length; j < jj; ++j) {
                 const glossary = glossaryList[j];
-                if (typeof glossary !== 'object' || glossary === null) { continue; }
+                if (typeof glossary !== 'object' || glossary === null || Array.isArray(glossary)) { continue; }
                 glossaryList[j] = this._formatDictionaryTermGlossaryObject(glossary, entry, requirements);
             }
             if ((i % formatProgressInterval) === 0) {
diff --git a/ext/js/display/display-generator.js b/ext/js/display/display-generator.js
index 3a2a5621..521cbb41 100644
--- a/ext/js/display/display-generator.js
+++ b/ext/js/display/display-generator.js
@@ -67,13 +67,13 @@ export class DisplayGenerator {
         const node = this._instantiate('term-entry');
 
         const headwordsContainer = this._querySelector(node, '.headword-list');
-        const inflectionsContainer = this._querySelector(node, '.inflection-list');
+        const inflectionRuleChainsContainer = this._querySelector(node, '.inflection-rule-chains');
         const groupedPronunciationsContainer = this._querySelector(node, '.pronunciation-group-list');
         const frequencyGroupListContainer = this._querySelector(node, '.frequency-group-list');
         const definitionsContainer = this._querySelector(node, '.definition-list');
         const headwordTagsContainer = this._querySelector(node, '.headword-list-tag-list');
 
-        const {headwords, type, inflections, definitions, frequencies, pronunciations} = dictionaryEntry;
+        const {headwords, type, inflectionRuleChainCandidates, definitions, frequencies, pronunciations} = dictionaryEntry;
         const groupedPronunciations = DictionaryDataUtil.getGroupedPronunciations(dictionaryEntry);
         const pronunciationCount = groupedPronunciations.reduce((i, v) => i + v.pronunciations.length, 0);
         const groupedFrequencies = DictionaryDataUtil.groupTermFrequencies(dictionaryEntry);
@@ -112,7 +112,7 @@ export class DisplayGenerator {
         }
         headwordsContainer.dataset.count = `${headwords.length}`;
 
-        this._appendMultiple(inflectionsContainer, this._createTermInflection.bind(this), inflections);
+        this._appendMultiple(inflectionRuleChainsContainer, this._createInflectionRuleChain.bind(this), inflectionRuleChainCandidates);
         this._appendMultiple(frequencyGroupListContainer, this._createFrequencyGroup.bind(this), groupedFrequencies, false);
         this._appendMultiple(groupedPronunciationsContainer, this._createGroupedPronunciation.bind(this), groupedPronunciations);
         this._appendMultiple(headwordTagsContainer, this._createTermTag.bind(this), termTags, headwords.length);
@@ -357,6 +357,44 @@ export class DisplayGenerator {
     }
 
     /**
+     * @param {import('dictionary').InflectionRuleChainCandidate} inflectionRuleChain
+     * @returns {?HTMLElement}
+     */
+    _createInflectionRuleChain(inflectionRuleChain) {
+        const {source, inflectionRules} = inflectionRuleChain;
+        if (!Array.isArray(inflectionRules) || inflectionRules.length === 0) { return null; }
+        const fragment = this._instantiate('inflection-rule-chain');
+
+        const sourceIcon = this._getInflectionSourceIcon(source);
+
+        fragment.appendChild(sourceIcon);
+
+        this._appendMultiple(fragment, this._createTermInflection.bind(this), inflectionRules);
+        return fragment;
+    }
+
+    /**
+     * @param {import('dictionary').InflectionSource} source
+     * @returns {HTMLElement}
+     */
+    _getInflectionSourceIcon(source) {
+        const icon = document.createElement('span');
+        icon.classList.add('inflection-source-icon');
+        icon.dataset.inflectionSource = source;
+        switch (source) {
+            case 'dictionary':
+                icon.title = 'Dictionary Deinflection';
+                return icon;
+            case 'algorithm':
+                icon.title = 'Algorithm Deinflection';
+                return icon;
+            case 'both':
+                icon.title = 'Dictionary and Algorithm Deinflection';
+                return icon;
+        }
+    }
+
+    /**
      * @param {string} inflection
      * @returns {DocumentFragment}
      */
@@ -396,7 +434,7 @@ export class DisplayGenerator {
     }
 
     /**
-     * @param {import('dictionary-data').TermGlossary} entry
+     * @param {import('dictionary-data').TermGlossaryContent} entry
      * @param {string} dictionary
      * @returns {?HTMLElement}
      */
diff --git a/ext/js/language/deinflector.js b/ext/js/language/deinflector.js
index d2d92e53..e2b66cb4 100644
--- a/ext/js/language/deinflector.js
+++ b/ext/js/language/deinflector.js
@@ -80,7 +80,7 @@ export class Deinflector {
     /**
      * @param {string} term
      * @param {import('translation-internal').DeinflectionRuleFlags} rules
-     * @param {string[]} reasons
+     * @param {import('dictionary').InflectionRuleChain} reasons
      * @returns {import('translation-internal').Deinflection}
      */
     _createDeinflection(term, rules, reasons) {
diff --git a/ext/js/language/translator.js b/ext/js/language/translator.js
index 5441294b..89a3e5ec 100644
--- a/ext/js/language/translator.js
+++ b/ext/js/language/translator.js
@@ -70,7 +70,7 @@ export class Translator {
     async findTerms(mode, text, options) {
         const {enabledDictionaryMap, excludeDictionaryDefinitions, sortFrequencyDictionary, sortFrequencyDictionaryOrder} = options;
         const tagAggregator = new TranslatorTagAggregator();
-        let {dictionaryEntries, originalTextLength} = await this._findTermsInternalWrapper(text, enabledDictionaryMap, options, tagAggregator);
+        let {dictionaryEntries, originalTextLength} = await this._findTermsInternal(text, enabledDictionaryMap, options, tagAggregator);
 
         switch (mode) {
             case 'group':
@@ -208,7 +208,7 @@ export class Translator {
      * @param {TranslatorTagAggregator} tagAggregator
      * @returns {Promise<import('translator').FindTermsResult>}
      */
-    async _findTermsInternalWrapper(text, enabledDictionaryMap, options, tagAggregator) {
+    async _findTermsInternal(text, enabledDictionaryMap, options, tagAggregator) {
         if (options.removeNonJapaneseCharacters) {
             text = this._getJapaneseOnlyText(text);
         }
@@ -216,18 +216,30 @@ export class Translator {
             return {dictionaryEntries: [], originalTextLength: 0};
         }
 
-        const deinflections = await this._findTermsInternal(text, enabledDictionaryMap, options);
+        const deinflections = await this._getDeinflections(text, enabledDictionaryMap, options);
 
         let originalTextLength = 0;
+        /** @type {import('dictionary').TermDictionaryEntry[]} */
         const dictionaryEntries = [];
         const ids = new Set();
-        for (const {databaseEntries, originalText, transformedText, deinflectedText, reasons} of deinflections) {
+        for (const {databaseEntries, originalText, transformedText, deinflectedText, inflectionRuleChainCandidates} of deinflections) {
             if (databaseEntries.length === 0) { continue; }
             originalTextLength = Math.max(originalTextLength, originalText.length);
             for (const databaseEntry of databaseEntries) {
                 const {id} = databaseEntry;
-                if (ids.has(id)) { continue; }
-                const dictionaryEntry = this._createTermDictionaryEntryFromDatabaseEntry(databaseEntry, originalText, transformedText, deinflectedText, reasons, true, enabledDictionaryMap, tagAggregator);
+                if (ids.has(id)) {
+                    const existingEntry = dictionaryEntries.find((entry) => {
+                        return entry.definitions.some((definition) => definition.id === id);
+                    });
+
+                    if (existingEntry && transformedText.length >= existingEntry.headwords[0].sources[0].transformedText.length) {
+                        this._mergeInflectionRuleChains(existingEntry, inflectionRuleChainCandidates);
+                    }
+
+                    continue;
+                }
+
+                const dictionaryEntry = this._createTermDictionaryEntryFromDatabaseEntry(databaseEntry, originalText, transformedText, deinflectedText, inflectionRuleChainCandidates, true, enabledDictionaryMap, tagAggregator);
                 dictionaryEntries.push(dictionaryEntry);
                 ids.add(id);
             }
@@ -237,40 +249,163 @@ export class Translator {
     }
 
     /**
+     * @param {import('dictionary').TermDictionaryEntry} existingEntry
+     * @param {import('dictionary').InflectionRuleChainCandidate[]} inflectionRuleChainCandidates
+     */
+    _mergeInflectionRuleChains(existingEntry, inflectionRuleChainCandidates) {
+        const existingChains = existingEntry.inflectionRuleChainCandidates;
+
+        for (const {source, inflectionRules} of inflectionRuleChainCandidates) {
+            const duplicate = existingChains.find((existingChain) => this._areArraysEqualIgnoreOrder(existingChain.inflectionRules, inflectionRules));
+            if (!duplicate) {
+                existingEntry.inflectionRuleChainCandidates.push({source, inflectionRules});
+            } else if (duplicate.source !== source) {
+                duplicate.source = 'both';
+            }
+        }
+    }
+
+    /**
+     * @param {string[]} array1
+     * @param {string[]} array2
+     * @returns {boolean}
+     */
+    _areArraysEqualIgnoreOrder(array1, array2) {
+        if (array1.length !== array2.length) {
+            return false;
+        }
+
+        const frequencyCounter = new Map();
+
+        for (const element of array1) {
+            frequencyCounter.set(element, (frequencyCounter.get(element) || 0) + 1);
+        }
+
+        for (const element of array2) {
+            const frequency = frequencyCounter.get(element);
+            if (!frequency) {
+                return false;
+            }
+            frequencyCounter.set(element, frequency - 1);
+        }
+
+        return true;
+    }
+
+
+    /**
      * @param {string} text
      * @param {Map<string, import('translation').FindTermDictionary>} enabledDictionaryMap
      * @param {import('translation').FindTermsOptions} options
      * @returns {Promise<import('translation-internal').DatabaseDeinflection[]>}
      */
-    async _findTermsInternal(text, enabledDictionaryMap, options) {
-        const deinflections = (
+    async _getDeinflections(text, enabledDictionaryMap, options) {
+        let deinflections = (
             options.deinflect ?
-            this._getAllDeinflections(text, options) :
+            this._getAlgorithmDeinflections(text, options) :
             [this._createDeinflection(text, text, text, 0, [])]
         );
         if (deinflections.length === 0) { return []; }
 
-        const uniqueDeinflectionTerms = [];
-        const uniqueDeinflectionArrays = [];
-        const uniqueDeinflectionsMap = new Map();
+        const {matchType} = options;
+
+        await this._addEntriesToDeinflections(deinflections, enabledDictionaryMap, matchType);
+
+        const dictionaryDeinflections = await this._getDictionaryDeinflections(deinflections, enabledDictionaryMap, matchType);
+        deinflections.push(...dictionaryDeinflections);
+
         for (const deinflection of deinflections) {
-            const term = deinflection.deinflectedText;
-            let deinflectionArray = uniqueDeinflectionsMap.get(term);
+            for (const entry of deinflection.databaseEntries) {
+                entry.definitions = entry.definitions.filter((definition) => !Array.isArray(definition));
+            }
+            deinflection.databaseEntries = deinflection.databaseEntries.filter((entry) => entry.definitions.length);
+        }
+        deinflections = deinflections.filter((deinflection) => deinflection.databaseEntries.length);
+
+        return deinflections;
+    }
+
+    /**
+     * @param {import('translation-internal').DatabaseDeinflection[]} deinflections
+     * @param {Map<string, import('translation').FindTermDictionary>} enabledDictionaryMap
+     * @param {import('dictionary').TermSourceMatchType} matchType
+     * @returns {Promise<import('translation-internal').DatabaseDeinflection[]>}
+     */
+    async _getDictionaryDeinflections(deinflections, enabledDictionaryMap, matchType) {
+        /** @type {import('translation-internal').DatabaseDeinflection[]} */
+        const dictionaryDeinflections = [];
+        for (const deinflection of deinflections) {
+            const {originalText, transformedText, inflectionRuleChainCandidates: algorithmChains, databaseEntries} = deinflection;
+            for (const entry of databaseEntries) {
+                const {dictionary, definitions} = entry;
+                const entryDictionary = enabledDictionaryMap.get(dictionary);
+                const useDeinflections = entryDictionary?.useDeinflections ?? true;
+                if (!useDeinflections) { continue; }
+                for (const definition of definitions) {
+                    if (Array.isArray(definition)) {
+                        const [formOf, inflectionRules] = definition;
+                        if (!formOf) { continue; }
+
+                        const inflectionRuleChainCandidates = algorithmChains.map(({inflectionRules: algInflections}) => {
+                            return {
+                                source: /** @type {import('dictionary').InflectionSource} */ (algInflections.length === 0 ? 'dictionary' : 'both'),
+                                inflectionRules: [...algInflections, ...inflectionRules]
+                            };
+                        });
+
+                        const dictionaryDeinflection = this._createDeinflection(originalText, transformedText, formOf, 0, inflectionRuleChainCandidates);
+                        dictionaryDeinflections.push(dictionaryDeinflection);
+                    }
+                }
+            }
+        }
+
+        await this._addEntriesToDeinflections(dictionaryDeinflections, enabledDictionaryMap, matchType);
+
+        return dictionaryDeinflections;
+    }
+
+    /**
+     * @param {import('translation-internal').DatabaseDeinflection[]} deinflections
+     * @param {Map<string, import('translation').FindTermDictionary>} enabledDictionaryMap
+     * @param {import('dictionary').TermSourceMatchType} matchType
+     */
+    async _addEntriesToDeinflections(deinflections, enabledDictionaryMap, matchType) {
+        const uniqueDeinflectionsMap = this._groupDeinflectionsByTerm(deinflections);
+        const uniqueDeinflectionArrays = [...uniqueDeinflectionsMap.values()];
+        const uniqueDeinflectionTerms = [...uniqueDeinflectionsMap.keys()];
+
+        const databaseEntries = await this._database.findTermsBulk(uniqueDeinflectionTerms, enabledDictionaryMap, matchType);
+        this._matchEntriesToDeinflections(databaseEntries, uniqueDeinflectionArrays, enabledDictionaryMap);
+    }
+
+    /**
+     * @param {import('translation-internal').DatabaseDeinflection[]} deinflections
+     * @returns {Map<string, import('translation-internal').DatabaseDeinflection[]>}
+     */
+    _groupDeinflectionsByTerm(deinflections) {
+        const result = new Map();
+        for (const deinflection of deinflections) {
+            const {deinflectedText} = deinflection;
+            let deinflectionArray = result.get(deinflectedText);
             if (typeof deinflectionArray === 'undefined') {
                 deinflectionArray = [];
-                uniqueDeinflectionTerms.push(term);
-                uniqueDeinflectionArrays.push(deinflectionArray);
-                uniqueDeinflectionsMap.set(term, deinflectionArray);
+                result.set(deinflectedText, deinflectionArray);
             }
             deinflectionArray.push(deinflection);
         }
+        return result;
+    }
 
-        const {matchType} = options;
-        const databaseEntries = await this._database.findTermsBulk(uniqueDeinflectionTerms, enabledDictionaryMap, matchType);
-
+    /**
+     * @param {import('dictionary-database').TermEntry[]} databaseEntries
+     * @param {import('translation-internal').DatabaseDeinflection[][]} uniqueDeinflectionArrays
+     * @param {Map<string, import('translation').FindTermDictionary>} enabledDictionaryMap
+     */
+    _matchEntriesToDeinflections(databaseEntries, uniqueDeinflectionArrays, enabledDictionaryMap) {
         for (const databaseEntry of databaseEntries) {
             const entryDictionary = /** @type {import('translation').FindTermDictionary} */ (enabledDictionaryMap.get(databaseEntry.dictionary));
-            const partsOfSpeechFilter = entryDictionary.partsOfSpeechFilter;
+            const {partsOfSpeechFilter} = entryDictionary;
 
             const definitionRules = Deinflector.rulesToRuleFlags(databaseEntry.rules);
             for (const deinflection of uniqueDeinflectionArrays[databaseEntry.index]) {
@@ -280,8 +415,6 @@ export class Translator {
                 }
             }
         }
-
-        return deinflections;
     }
 
     // Deinflections and text transformations
@@ -291,7 +424,7 @@ export class Translator {
      * @param {import('translation').FindTermsOptions} options
      * @returns {import('translation-internal').DatabaseDeinflection[]}
      */
-    _getAllDeinflections(text, options) {
+    _getAlgorithmDeinflections(text, options) {
         /** @type {import('translation-internal').TextDeinflectionOptionsArrays} */
         const textOptionVariantArray = [
             this._getTextReplacementsVariants(options),
@@ -342,7 +475,12 @@ export class Translator {
                 used.add(source);
                 const rawSource = sourceMap.source.substring(0, sourceMap.getSourceLength(i));
                 for (const {term, rules, reasons} of /** @type {Deinflector} */ (this._deinflector).deinflect(source)) {
-                    deinflections.push(this._createDeinflection(rawSource, source, term, rules, reasons));
+                    /** @type {import('dictionary').InflectionRuleChainCandidate} */
+                    const inflectionRuleChainCandidate = {
+                        source: 'algorithm',
+                        inflectionRules: reasons
+                    };
+                    deinflections.push(this._createDeinflection(rawSource, source, term, rules, [inflectionRuleChainCandidate]));
                 }
             }
         }
@@ -435,11 +573,11 @@ export class Translator {
      * @param {string} transformedText
      * @param {string} deinflectedText
      * @param {import('translation-internal').DeinflectionRuleFlags} rules
-     * @param {string[]} reasons
+     * @param {import('dictionary').InflectionRuleChainCandidate[]} inflectionRuleChainCandidates
      * @returns {import('translation-internal').DatabaseDeinflection}
      */
-    _createDeinflection(originalText, transformedText, deinflectedText, rules, reasons) {
-        return {originalText, transformedText, deinflectedText, rules, reasons, databaseEntries: []};
+    _createDeinflection(originalText, transformedText, deinflectedText, rules, inflectionRuleChainCandidates) {
+        return {originalText, transformedText, deinflectedText, rules, inflectionRuleChainCandidates, databaseEntries: []};
     }
 
     // Term dictionary entry grouping
@@ -597,8 +735,8 @@ export class Translator {
     _groupDictionaryEntriesByHeadword(dictionaryEntries, tagAggregator) {
         const groups = new Map();
         for (const dictionaryEntry of dictionaryEntries) {
-            const {inflections, headwords: [{term, reading}]} = dictionaryEntry;
-            const key = this._createMapKey([term, reading, ...inflections]);
+            const {inflectionRuleChainCandidates, headwords: [{term, reading}]} = dictionaryEntry;
+            const key = this._createMapKey([term, reading, ...inflectionRuleChainCandidates]);
             let groupDictionaryEntries = groups.get(key);
             if (typeof groupDictionaryEntries === 'undefined') {
                 groupDictionaryEntries = [];
@@ -1370,7 +1508,7 @@ export class Translator {
      * @param {number[]} sequences
      * @param {boolean} isPrimary
      * @param {import('dictionary').Tag[]} tags
-     * @param {import('dictionary-data').TermGlossary[]} entries
+     * @param {import('dictionary-data').TermGlossaryContent[]} entries
      * @returns {import('dictionary').TermDefinition}
      */
     _createTermDefinition(index, headwordIndices, dictionary, dictionaryIndex, dictionaryPriority, id, score, sequences, isPrimary, tags, entries) {
@@ -1421,7 +1559,7 @@ export class Translator {
 
     /**
      * @param {boolean} isPrimary
-     * @param {string[]} inflections
+     * @param {import('dictionary').InflectionRuleChainCandidate[]} inflectionRuleChainCandidates
      * @param {number} score
      * @param {number} dictionaryIndex
      * @param {number} dictionaryPriority
@@ -1431,11 +1569,11 @@ export class Translator {
      * @param {import('dictionary').TermDefinition[]} definitions
      * @returns {import('dictionary').TermDictionaryEntry}
      */
-    _createTermDictionaryEntry(isPrimary, inflections, score, dictionaryIndex, dictionaryPriority, sourceTermExactMatchCount, maxTransformedTextLength, headwords, definitions) {
+    _createTermDictionaryEntry(isPrimary, inflectionRuleChainCandidates, score, dictionaryIndex, dictionaryPriority, sourceTermExactMatchCount, maxTransformedTextLength, headwords, definitions) {
         return {
             type: 'term',
             isPrimary,
-            inflections,
+            inflectionRuleChainCandidates,
             score,
             frequencyOrder: 0,
             dictionaryIndex,
@@ -1454,14 +1592,29 @@ export class Translator {
      * @param {string} originalText
      * @param {string} transformedText
      * @param {string} deinflectedText
-     * @param {string[]} reasons
+     * @param {import('dictionary').InflectionRuleChainCandidate[]} inflectionRuleChainCandidates
      * @param {boolean} isPrimary
      * @param {Map<string, import('translation').FindTermDictionary>} enabledDictionaryMap
      * @param {TranslatorTagAggregator} tagAggregator
      * @returns {import('dictionary').TermDictionaryEntry}
      */
-    _createTermDictionaryEntryFromDatabaseEntry(databaseEntry, originalText, transformedText, deinflectedText, reasons, isPrimary, enabledDictionaryMap, tagAggregator) {
-        const {matchType, matchSource, term, reading: rawReading, definitionTags, termTags, definitions, score, dictionary, id, sequence: rawSequence, rules} = databaseEntry;
+    _createTermDictionaryEntryFromDatabaseEntry(databaseEntry, originalText, transformedText, deinflectedText, inflectionRuleChainCandidates, isPrimary, enabledDictionaryMap, tagAggregator) {
+        const {
+            matchType,
+            matchSource,
+            term,
+            reading: rawReading,
+            definitionTags,
+            termTags,
+            definitions,
+            score,
+            dictionary,
+            id,
+            sequence: rawSequence,
+            rules
+        } = databaseEntry;
+        // cast is safe because getDeinflections filters out deinflection definitions
+        const contentDefinitions = /** @type {import('dictionary-data').TermGlossaryContent[]} */ (definitions);
         const reading = (rawReading.length > 0 ? rawReading : term);
         const {index: dictionaryIndex, priority: dictionaryPriority} = this._getDictionaryOrder(dictionary, enabledDictionaryMap);
         const sourceTermExactMatchCount = (isPrimary && deinflectedText === term ? 1 : 0);
@@ -1479,14 +1632,14 @@ export class Translator {
 
         return this._createTermDictionaryEntry(
             isPrimary,
-            reasons,
+            inflectionRuleChainCandidates,
             score,
             dictionaryIndex,
             dictionaryPriority,
             sourceTermExactMatchCount,
             maxTransformedTextLength,
             [this._createTermHeadword(0, term, reading, [source], headwordTagGroups, rules)],
-            [this._createTermDefinition(0, [0], dictionary, dictionaryIndex, dictionaryPriority, id, score, [sequence], isPrimary, definitionTagGroups, definitions)]
+            [this._createTermDefinition(0, [0], dictionary, dictionaryIndex, dictionaryPriority, id, score, [sequence], isPrimary, definitionTagGroups, contentDefinitions)]
         );
     }
 
@@ -1530,7 +1683,7 @@ export class Translator {
             if (dictionaryEntry.isPrimary) {
                 isPrimary = true;
                 maxTransformedTextLength = Math.max(maxTransformedTextLength, dictionaryEntry.maxTransformedTextLength);
-                const dictionaryEntryInflections = dictionaryEntry.inflections;
+                const dictionaryEntryInflections = dictionaryEntry.inflectionRuleChainCandidates;
                 if (inflections === null || dictionaryEntryInflections.length < inflections.length) {
                     inflections = dictionaryEntryInflections;
                 }
@@ -1742,7 +1895,7 @@ export class Translator {
             if (i !== 0) { return i; }
 
             // Sort by the number of inflection reasons
-            i = v1.inflections.length - v2.inflections.length;
+            i = v1.inflectionRuleChainCandidates.length - v2.inflectionRuleChainCandidates.length;
             if (i !== 0) { return i; }
 
             // Sort by how many terms exactly match the source (e.g. for exact kana prioritization)
diff --git a/ext/js/pages/settings/dictionary-controller.js b/ext/js/pages/settings/dictionary-controller.js
index 18a802be..1d3da532 100644
--- a/ext/js/pages/settings/dictionary-controller.js
+++ b/ext/js/pages/settings/dictionary-controller.js
@@ -185,6 +185,10 @@ class DictionaryEntry {
         const partsOfSpeechFilterSetting = querySelectorNotNull(modal.node, '.dictionary-parts-of-speech-filter-setting');
         /** @type {HTMLElement} */
         const partsOfSpeechFilterToggle = querySelectorNotNull(partsOfSpeechFilterSetting, '.dictionary-parts-of-speech-filter-toggle');
+        /** @type {HTMLElement} */
+        const useDeinflectionsSetting = querySelectorNotNull(modal.node, '.dictionary-use-deinflections-setting');
+        /** @type {HTMLElement} */
+        const useDeinflectionsToggle = querySelectorNotNull(useDeinflectionsSetting, '.dictionary-use-deinflections-toggle');
 
         titleElement.textContent = title;
         versionElement.textContent = `rev.${revision}`;
@@ -194,6 +198,9 @@ class DictionaryEntry {
         partsOfSpeechFilterSetting.hidden = !counts.terms.total;
         partsOfSpeechFilterToggle.dataset.setting = `dictionaries[${this._index}].partsOfSpeechFilter`;
 
+        useDeinflectionsSetting.hidden = !counts.terms.total;
+        useDeinflectionsToggle.dataset.setting = `dictionaries[${this._index}].useDeinflections`;
+
         this._setupDetails(detailsTableElement);
 
         modal.setVisible(true);
@@ -521,7 +528,8 @@ export class DictionaryController {
             enabled,
             allowSecondarySearches: false,
             definitionsCollapsible: 'not-collapsible',
-            partsOfSpeechFilter: true
+            partsOfSpeechFilter: true,
+            useDeinflections: true
         };
     }
 
diff --git a/ext/js/templates/sandbox/anki-template-renderer.js b/ext/js/templates/sandbox/anki-template-renderer.js
index 3311097f..e4822bee 100644
--- a/ext/js/templates/sandbox/anki-template-renderer.js
+++ b/ext/js/templates/sandbox/anki-template-renderer.js
@@ -675,7 +675,7 @@ export class AnkiTemplateRenderer {
      * @type {import('template-renderer').HelperFunction<string>}
      */
     _formatGlossary(args, _context, options) {
-        const [dictionary, content] = /** @type {[dictionary: string, content: import('dictionary-data').TermGlossary]} */ (args);
+        const [dictionary, content] = /** @type {[dictionary: string, content: import('dictionary-data').TermGlossaryContent]} */ (args);
         const data = options.data.root;
         if (typeof content === 'string') { return this._stringToMultiLineHtml(this._escape(content)); }
         if (!(typeof content === 'object' && content !== null)) { return ''; }
diff --git a/ext/settings.html b/ext/settings.html
index 2cc521d5..3a4c90ce 100644
--- a/ext/settings.html
+++ b/ext/settings.html
@@ -2691,6 +2691,24 @@
             </div>
         </div>
         <hr>
+        <div class="settings-item dictionary-use-deinflections-setting" hidden>
+            <div class="settings-item-inner">
+                <div class="settings-item-left">
+                    <div class="settings-item-label">
+                        Use deinflections
+                        <a tabindex="0" class="more-toggle more-only" data-parent-distance="4">(?)</a>
+                    </div>
+                </div>
+                <div class="settings-item-right">
+                    <label class="toggle"><input type="checkbox" class="dictionary-use-deinflections-toggle"><span class="toggle-body"><span class="toggle-track"></span><span class="toggle-knob"></span></span></label>
+                </div>
+            </div>
+            <div class="settings-item-children more" hidden>
+                Deinflections from this dictionary will be used.
+                <p><a tabindex="0" class="more-toggle" data-parent-distance="3">Hide&hellip;</a></p>
+            </div>
+        </div>
+        <hr>
         <div class="settings-item"><div class="settings-item-children">
             <div class="dictionary-details-table"></div>
             <div class="dictionary-counts"></div>