thesaurus

[thi-sawr-uhs]

noun

plural

thesauruses, thesauri 

1. a dictionary of synonyms and antonyms, such as the online Thesaurus.com.

2. any dictionary, encyclopedia, or other comprehensive reference book.

3. a storehouse, repository, or treasury.

4. Computers.

   1. an index to information stored in a computer, consisting of a comprehensive list of subjects concerning which information may be retrieved by using the proper key terms.

   2. a dictionary of synonyms and antonyms stored in memory for use in word processing.

thesaurus

/ θɪˈsɔːrəs /

noun

1. a book containing systematized lists of synonyms and related words

2. a dictionary of selected words or topics

3. rare,  a treasury

Word History and Origins

Origin of thesaurus¹

First recorded in 1730–40; from Latin thēsaurus, from Greek thēsaurós “treasure, treasury”

Word History and Origins

Origin of thesaurus¹

C18: from Latin, Greek: _treasure

Example Sentences

As the authors write, he turned to the thesaurus and made lists of traditional “pirating” words.

Read more on Los Angeles Times

She undoubtedly has a thesaurus earmarked and highlighted like a high school student’s SparkNotes copy of “Macbeth.”

Read more on Salon

Stevens raised challenges in dozens of school districts over the Bible, dictionaries and thesauruses.

Read more on Seattle Times

And now you can break out the thesaurus.

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Critics thumbed thesauruses for hyperboles to rhapsodize about her pyrotechnics.

Read more on New York Times

Related Words

• reference book 

When To Use

What is a thesaurus?

A thesaurus is a book or program that lists synonyms and antonyms of words.A thesaurus can be a book you can find in a library, a website (such as Thesaurus.com), or a database stored in a word processor (such as the one you can find in Microsoft Word). The plural of thesaurus is thesauruses or thesauri.A synonym is a word that has the same meaning as another word. For example, huge, gigantic, massive, and large are synonyms of the word big. An antonym is a word that has the opposite meaning of another word. Small, tiny, and little are antonyms of the word big.Thesauri are useful when you want to avoid using the same word over and over or need a fancy word to describe something as being “not good” or “not fun.”