thesaurus (a) a book of words or of information about a particular field or set of concepts especially : a book of words and their synonyms (b) a list of subject headings or descriptors usually with a cross-reference system for use in the organization of a collection of documents for reference and retrieval — Webster
Thesaurus (plural thesauri or thesauruses) or synonym dictionary is a reference work for finding synonyms and sometimes antonyms of words. — Wikipedia
The Right Word: Roget and his thesaurus (Jennifer Bryant and Melissa Sweet, Eerdmans Books for Young Readers)
Roget’s II: The New Thesaurus, 3rd Ed. (Thesaurus.com, Houghton Mifflin)
Roget’s International Thesaurus of English Words and Phrases, 1922 Edition (C. O. Sylvester Mawson, Bartleby)
Roget’s Thesaurus (Wikipedia)
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