from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A book of synonyms, often including related and contrasting words and antonyms.
- n. A book of selected words or concepts, such as a specialized vocabulary of a particular field, as of medicine or music.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language.
- n. A dictionary or encyclopedia.
- n. A hierarchy of subject headings—canonic titles of themes and topics, the titles serving as search keys.
from the GNU version of the Collaborative International Dictionary of English
- n. A treasury or storehouse; hence, a repository, especially of knowledge; -- often applied to a comprehensive work, like a dictionary or cyclopedia.
from The Century Dictionary and Cyclopedia
- n. A treasury; a store; especially, thesaurus verborum, or simply thesaurus, a treasury of words; a lexicon.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a book containing a classified list of synonyms
Latin thēsaurus, treasury, from Greek thēsauros.(American Heritage® Dictionary of the English Language, Fourth Edition)
16th century, from Latin thēsaurus, from Ancient Greek θησαυρός (thēsauros, "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 (Wiktionary)