Functionality
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 or IPA), or British English (IPA).
The dictionary and thesaurus in Dictionary are in an XML format, but make use of precompiled binary index files to access the XML file directly. Therefore, the lexicon cannot easily be modified. However, the user can add new words to the Mac OS X system-wide spell checker, which uses its own lexicon.
Read more about this topic: Dictionary (software)