thesaurus

American  

[thi-sawr-uhs] / θɪˈsɔr əs /

noun

thesauruses, plural thesauri plural

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.

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thesaurus British  

/ 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

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Usage

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.”

Other Word Forms

Noun Inflected Forms

• thesauri
  plural
• thesauruses
  plural

Etymology

Origin of thesaurus

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

Explanation

A thesaurus is a reference book (or a really cool website, like the Visual Thesaurus) with an organized list of words and their synonyms. An Englishman named Peter Roget published the first modern English thesaurus in 1852. Roget had severe depression, and one of the ways he coped was to put his list-making and lexicographical (word analyzing) skills to use in a reference book that would group words, not alphabetically, but according to how similar their meanings were. This being the middle of the 19th century, there were no computers: Roget compiled and sorted all of his lists by hand.

Example Sentences

See Examples For:

thesaurus thesauri thesauruses

And now you can break out the thesaurus.

From Los Angeles Times ● Mar. 20, 2024

At their simplest, these programs mask plagiarism through liberal use of a thesaurus; replace enough words with synonyms and hopefully nobody will ever find the original source.

From Scientific American ● Sep. 28, 2023

A charge against you isn't merely false, it's totally false or completely bogus, or some such, from the liar's well-thumbed thesaurus.

From Salon ● May 6, 2023

It was helpful the way a thesaurus or Google is, offering inspiration for what to write.

From Slate ● Mar. 2, 2023

Friend was a strong word, but now wasn’t the time to get a thesaurus.

From "Millionaires for the Month" by Stacey McAnulty

Let's give thesauri to all songwriters incapable of dreaming up more original ways to voice that sentiment.

From Time Magazine Archive

Nor do its plural forms, the highfalutin thesauri, or thesauruses, which sounds like a prehistoric creature.

From Time Magazine Archive

Why, at the moment the audience should be melting into tears over the death of this salesman, does the playwright introduce a word that sets viewers to thumbing their internal thesauri?

From Time Magazine Archive

Ratings plummeted after the first episode, and critics dug out their thesauri to find new words for "awful."

From Time Magazine Archive

There were then no short cuts of learning, no comprehensive lexicons, no dictionaries of antiquities, no carefully prepared thesauri of mythology and history.

From The Great Events by Famous Historians, Volume 07 by Johnson, Rossiter

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

From Seattle Times ● Apr. 16, 2024

Amin said because some countries, particularly poorer ones may see phase-out as too restrictive, negotiators could even hit their thesauruses for alternatives to the much discussed phase-out or phase-down wording.

From Seattle Times ● Dec. 5, 2023

Take a good look as they don 10-ounce thesauruses packed full of slander.

From The Guardian ● Jun. 20, 2017

Later, he worked on encyclopedias and thesauruses, becoming one of America’s leading lexicographers.

From New York Times ● Apr. 26, 2015

Nor do its plural forms, the highfalutin thesauri, or thesauruses, which sounds like a prehistoric creature.

From Time Magazine Archive

Related Words

• reference book