Best Free Dictionary and Thesaurus for Android

Dictionary - Merriam-Webster (20 MB), type in or speak a word to look up its definitions, audio pronunciations, example sentences, synonyms and antonyms which are accessible offline. Most words including highlighted ones are hyperlinked for a tap to search deeper. Other features include Daily Word and Recent Searches. Ad-supported.
 
Dictionary.com (3.6 MB), includes more than 2 million definitions and synonyms from Dictionary.com and Thesaurus.com, with audio pronunciation, voice-to-text search, hyperlinked words, favorite words list, Word of the Day, homescreen widget, offline dictionary, etc. Ad-supported.
 
Arcus Dictionary (6.3 MB), fast and ad-free dictionary with more than 165,000 words, definitions and synonyms without requiring network access after install, supports for text-to-speech, word hyperlinks, favorites and other options.
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