/thi sawr"euhs/ , n. , pl. thesauruses, thesauri /-sawr"uy/ .
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.
[ 1730-40; thesaurus thesaurós treasure, treasury ]