(plural thesauri or thesauruses)
- A publication, usually in the form of a book, that provides synonyms (sometimes antonyms) for the words of a given language.
- "Roget" is the leading brand name for a print English thesaurus that lists words under general concepts rather than just close synonyms.
- (archaic) A dictionary or encyclopedia.
- (information science) A hierarchy of subject headings"”canonic titles of themes and topics, the titles serving as search keys.
16th century, from Latin thÄ“saurus, from Ancient Greek Î¸Î·ÏƒÎ±Ï…ÏÏŒÏ‚ (thÄ“sauros, “storehouse, treasure"); its current English usage/meaning was established soon after the publication of Peter Roget's Thesaurus of English Words and Phrases in 1852