TheSage's English Dictionary and Thesaurus runs locally, and does not use your Internet connection. The Dictionary comprises more than 145,000 references with multiple detailed definitions (over 200,000); A large collection of examples of usage (approx. 35,000); Encyclopedic information (geographical, historical, political,...); Academic knowledge (medicine, biology,... ).

The Thesaurus encompasses synonyms, antonyms, hypernyms, hyponyms, meronyms, holonyms,...; Nearly 1,200,000 relationships between definitions. The essential functionality includes the following: Tabbed interface allowing multiple definitions and searches to be readily available; Quick cross-referencing (any and all displayed words are clickable, triggering a lookup); Standard and advanced wildcard search functionality; Anagram search; History and session record keeping; Options that allow customization of the appearance of TheSage; Copy to clipboard of all or part of the information displayed.