thesaurus

For the Wiktionary thesaurus, see Wiktionary:Wikisaurus

Noun

thesaurus (plural thesauri or thesauruses)

1. A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language.

   "Roget" is the leading brand name for a print English thesaurus.

2. (archaic) A dictionary or encyclopedia.
3. (information science) A hierarchy of subject headings—canonic titles of themes and topics, the titles serving as search keys.

Synonyms

• synonymicon

Derived terms

• thesaural

A thesaurus is a book that lists words grouped together according to similarity of meaning (containing synonyms and sometimes antonyms), in contrast to a dictionary, which contains definitions and pronunciations. The largest thesaurus in the world is the Historical Thesaurus of the Oxford English Dictionary, which contains more than 920,000 words.