Pronunciation: (thi-sôr'us),[key] —n., —pl.-sau•rus•es, -sau•riPronunciation: (-sôr'ī).[key] 1. a dictionary of synonyms and antonyms.
2. any dictionary, encyclopedia, or other comprehensive reference book.
3. a storehouse, repository, or treasury.
4. Computers. a. an index to information stored in a computer, consisting of a comprehensive list of subjects concerning which information may be retrieved by using the proper key terms.
b. a dictionary of synonyms and antonyms stored in memory for use in word processing.