Dictionary is anapplication developed byApple Inc. as a part ofmacOS. The application provides definitions and synonyms from various dictionaries,Wikipedia articles and a glossary of Apple-related terms.

Dictionary

Dictionary running onmacOS 11
Developer(s)	Apple Inc.
Stable release	2.3.0 / August 18, 2018; 6 years ago (2018-08-18)[1]
Operating system	macOS
Type	Dictionary
License	Proprietary
Website	support.apple.com/ja-jp/guide/dictionary/welcome/mac

Dictionary was introduced inOS X 10.4 with theNew Oxford American Dictionary andOxford American Writer's Thesaurus (as well as theWikipedia andApple Dictionary sections).10.5 added Japanese dictionaries,10.7 added the BritishOxford Dictionary of English, and10.8 added French, German, Spanish and Chinese.

OS X's progenitor,OPENSTEP (andNEXTSTEP) provided similar functionality, called Digital Webster, providingdictionary andthesaurus definitions fromWebster's Ninth New Collegiate Dictionary and Webster's Collegiate Thesaurus (termed the "First Digital Edition"). OPENSTEP Services provide lookup from all applications.

Dictionary was first introduced withMac OS X v10.4 "Tiger" and provided definitions from theNew Oxford American Dictionary, 2nd Edition. WithMac OS X 10.7 "Lion", Dictionary was updated to the Third Edition of theNew Oxford American Dictionary and the BritishOxford Dictionary of English was added.^[2]

Words can be entered in the search bar by just typing the first few letters. The application will perform an incremental search to show any matching headwords or forms and will try to bypass spelling errors. Clicking on any word in a definition searches for that word in the dictionary again. Almost any word is clickable, except the pronunciations in phonetic characters and numerals.

The Preferences allow a user to select from three different pronunciation schemes, either US English (Diacritical orIPA), or British English (IPA).

The dictionary and thesaurus in Dictionary are in anXML format, but make use of precompiled binary index files to access the XML file directly. Therefore, thelexicon cannot easily be modified. However, the user can add new words to the macOS system-widespell checker, which uses its own lexicon.

• In applications which support "Services", there is an option in the application menu (for example, Safari>Services>Look up in Dictionary) which brings up the Dictionary application and displays the definition of a selected word. The same option appears in thecontextual menu after a Control-click on the selected word.
• The key combinationcontrol+⌘ Command+D can be used inCocoa applications which display text – it brings up a small contextual menu-like definition or synonym of the word under thecursor.
• As ofMac OS X Lion, a three finger tap on the trackpad (either the built-inMacBook trackpad or theMagic Trackpad) has the same effect as thecontrol+⌘ Command+D shortcut.
• In applications which support the ability of the user to drag selected text, it is possible to select a word and drop it onto the icon of the Dictionary application in theDock.
• Dashboard includes awidget for accessing the Dictionary application.
• macOS catches any queries to thedict:// URI scheme, say from a web browser, and routes them back to the Dictionary application.
• SinceOS X Leopard, the dictionary has become tightly integrated withSpotlight, allowing users to view definitions from immediately within the system search.^[3]

Mac OS X 10.5 (Leopard) added the Japanese-language dictionaryDaijisen, Progressive English to Japanese and Progressive Japanese to English dictionaries, and the 25,000-entry thesaurus "Tsukaikata no Wakaru Ruigo Reikai Jiten" (使い方の分かる類語例解辞典), all of which are provided by the Japanese publisherShogakukan. The Japanese dictionaries do not show up by default, and must be enabled in Preferences.

InOS X 10.8 Mountain Lion, the Japanese dictionaries were replaced by Super Daijirin and the Wisdom English-Japanese Dictionary. In addition, dictionaries were also added for French (Multidictionnaire de la Langue Française for Macs sold in Europe, orLes Éditions Québec Amérique for Macs sold in America), German (Duden), Spanish (Vox), and Chinese (Standard Dictionary of Contemporary Chinese).

Software such as DictUnifier^[4] can be used to add more dictionaries to the application.

• Install dictionaries on Mac OS X - YouTube