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Definition of thesaurus

thesaurus

/θɪˈsɔːr.əs/
the · sau · rus
Plural:thesauruses
•
Adjective:thesaural
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thesaurus Lexical Profile

thesaurus Game Scores & Validity

• noun

1

A reference book or digital resource that lists words in groups of synonyms, related concepts, and often antonyms.

Example

"She consulted a thesaurus to find a more precise adjective for her essay."

2

A comprehensive storehouse, treasury, or encyclopedia of knowledge on a particular subject.

Example

"The multi-volume work serves as an exhaustive thesaurus of ancient botanical lore."

Synonyms
View all synonyms for thesaurus

Word Nuance & Usage

Both the regular English plural 'thesauruses' and the Latinate plural 'thesauri' are standard and widely accepted in modern usage.

• Rhymes for thesaurus

• Nearby Words

thermostat
thermostatic
thermostatically
thesaurus
thesis
thespesia
thespian

Word Origin & Etymology

Borrowed in the late 16th century from Latin 'thesaurus', from Ancient Greek 'thesauros' meaning 'storehouse' or 'treasure'. The modern sense of a book of synonyms was popularized by Peter Mark Roget's 1852 publication.

Cite this Entry

Wordmom. (2026). Definition of Thesaurus. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/thesaurus
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