the·​sau·​rus | \ thi-ˈsȯr-əs How to pronounce thesaurus (audio) \
plural thesauri\ thi-​ˈsȯr-​ˌī How to pronounce thesaurus (audio) , -​ˌē \ or thesauruses\ thi-​ˈsȯr-​ə-​səz How to pronounce thesaurus (audio) \

Essential Meaning of thesaurus

: a book in which words that have the same or similar meanings are grouped together

Full Definition of thesaurus

1a : 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

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Other Words from thesaurus

thesaural \ thi-​ˈsȯr-​əl How to pronounce thesaurus (audio) \ adjective

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In the early 19th century, archaeologists borrowed the Latin word thesaurus to denote an ancient treasury, such as that of a temple. Soon after, the word was metaphorically applied to a book containing a "treasury" of words or information about a particular field. In 1852, the English scholar Peter Mark Roget published his Thesaurus of English Words and Phrases, in which he listed a treasury of related words organized into numerous categories. This work led to the common acceptance of the term "thesaurus" for "a book of words and their synonyms." Finally, during the 1950s, "thesaurus" began being used in the field of word processing to refer to a list of related terms used for indexing and retrieval.

Examples of thesaurus in a Sentence

Recent Examples on the Web Over-the-top rhetoric that sounds as if someone locked Kiley in a room with a thesaurus, but doesn’t really conform to what even Newsom’s critics think of his performance. Michael Hiltzik, Los Angeles Times, 15 Sep. 2021 Books, including a thesaurus so tattered from use that back when there were regular tours of the newsroom, the tour guide would show it to visitors. Karina Bland, The Arizona Republic, 23 June 2021 Synonymy—the concept of distinct words signifying the same thing—was understood as far back as Ancient Greece, but the Archbishop of Seville authored the earliest work modern readers might recognize as a thesaurus. Claudia Kalb, Smithsonian Magazine, 21 Apr. 2021 Spending meaningful time with a thesaurus while also seeking out professional branding identity experts is advisable. Expert Panel®, Forbes, 7 Apr. 2021 Grab your thesaurus and look up another word for bad, another word for tragic. Gregg Doyel, Indianapolis Star, 13 Apr. 2020 Flip through a thesaurus or take online quizzes to test your vocabulary, and gradually intumesce your personal lexicon and chevvy your kin with your verbosity. Scottie Andrew, CNN, 14 Mar. 2020 Like a thesaurus or maybe War and Peace (sorry, Tolstoy). - Open the cover and first few pages and secure the remaining pages with clamps. Popular Mechanics Editors, Popular Mechanics, 22 Feb. 2020 The event prompted a thesaurus’s load of invective. Clifton Leaf, Fortune, 11 Feb. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thesaurus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of thesaurus

circa 1823, in the meaning defined at sense 2

History and Etymology for thesaurus

New Latin, from Latin, treasure, collection, from Greek thēsauros

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Time Traveler for thesaurus

Time Traveler

The first known use of thesaurus was circa 1823

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Dictionary Entries Near thesaurus



the scenic route

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Statistics for thesaurus

Last Updated

27 Sep 2021

Cite this Entry

“Thesaurus.” Dictionary, Merriam-Webster, Accessed 27 Sep. 2021.

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More Definitions for thesaurus


the·​sau·​rus | \ thi-ˈsȯr-əs How to pronounce thesaurus (audio) \
plural thesauri\ -​ˈsȯr-​ˌī , -​ˌē \ or thesauruses\ -​ˈsȯr-​ə-​səz \

Kids Definition of thesaurus

: a book of words and their synonyms


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