thesaurus
Americannoun
plural
thesauruses, thesauri-
a dictionary of synonyms and antonyms, such as the online Thesaurus.com.
-
any dictionary, encyclopedia, or other comprehensive reference book.
-
a storehouse, repository, or treasury.
-
Computers.
-
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.
-
a dictionary of synonyms and antonyms stored in memory for use in word processing.
-
noun
-
a book containing systematized lists of synonyms and related words
-
a dictionary of selected words or topics
-
rare a treasury
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.”
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.
Vocabulary lists containing thesaurus
TEKS ELAR Academic Vocabulary List (5th-7th grades)
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Language and Grammar - Introductory
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
New Year, New Words: Vocabulary for January
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Crosby wants Roget's Thesaurus because with that, and a sharp stick, "I could do some useful writing".
From BBC • Oct. 12, 2022
One exception he found: Lester Berrey’s 1947 “American Thesaurus of Slang” includes many nicknames for California, including “Eureka State,” “Golden Poppy State,” “Land of Perpetual Sunshine” and, yes, “Cali.”
From Los Angeles Times • Jun. 1, 2022
Among the antonyms for “nice” in Roget’s Thesaurus are “ugly,” “horrible,” “nasty” and “repulsive.”
From Washington Post • Dec. 20, 2020
Denver special teams coach Tom McMahon, who described his unit’s play at Pittsburgh as “one word: terrible,” won’t need a Thesaurus for this one.
From Seattle Times • Sep. 27, 2020
I had a most frightful dream, and it was not due to Welsh-rarebits, but to my fatal weakness, which, not having my Thesaurus at hand, I must identify by the commonplace term of courtesy.
From The Inventions of the Idiot by Bangs, John Kendrick
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.