id·​i·​o·​syn·​cra·​sy | \ˌi-dē-ə-ˈsiŋ-krə-sē \
plural idiosyncrasies

Definition of idiosyncrasy 

1a : a peculiarity of constitution or temperament : an individualizing characteristic or quality

b : individual hypersensitiveness (as to a drug or food)

2 : characteristic peculiarity (as of temperament) broadly : eccentricity

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Other Words from idiosyncrasy

idiosyncratic \ˌi-​dē-​ō-​(ˌ)sin-​ˈkra-​tik \ adjective
idiosyncratically \ˌi-​dē-​ō-​(ˌ)sin-​ˈkra-​ti-​k(ə-​)lē \ adverb

Examples of idiosyncrasy in a Sentence

Her habit of using “like” in every sentence was just one of her idiosyncrasies. The current system has a few idiosyncracies.

Recent Examples on the Web

Drivers will need to learn its idiosyncrasies, which Hotz argues is the same for any modern, high-tech car on the road today. Andrew J. Hawkins, The Verge, "George Hotz is on a hacker crusade against the ‘scam’ of self-driving cars," 13 July 2018 Moore dutifully attacks the idiosyncrasies of the system, like the Electoral College and the Democratic Party’s system of superdelegates. Alissa Wilkinson, Vox, "In Fahrenheit 11/9, Michael Moore spares no one — especially self-satisfied liberals," 7 Sep. 2018 Robin Brooks, the chief economist of the IIF, said Turkey is an extreme case, but cautioned against taking too much comfort in its idiosyncrasies. Josh Zumbrun, WSJ, "Turkey’s Economic Red Flags Stand Out Among Emerging Markets," 15 Aug. 2018 And splashy canvases by Zhang Wei, who was born in 1952, have a careless dynamism and personal idiosyncrasy that Wu would have appreciated. Jason Farago, Martha Schwendener And Will Heinrich, New York Times, "What to See in New York Art Galleries This Week," 5 Apr. 2018 By the start of season two, GLOW’s cast has developed the sort of intimacy particular to those who are abruptly thrown together and tasked with creating art, all the while wading through one another’s idiosyncrasies and prejudices. Rachel Vorona Cote, The New Republic, "In GLOW, Who Gets To Be Empowered?," 28 June 2018 Trudeau’s critics still love to complain about his cutesy idiosyncrasies: wearing flashy socks, for example, being frequently seen shirtless in public, or photo-bombing regular Canadians. Selena Ross, Washington Post, "Trudeau takes his turn as Trump’s principal antagonist, and Canadians rally around," 10 June 2018 Trudeau's critics still love to complain about his cutesy idiosyncrasies: wearing flashy socks, being seen shirtless in public, or photobombing regular Canadians. Author: Selena Ross, Anchorage Daily News, "Trudeau takes his turn as Trump's principal antagonist, and Canadians rally around him," 10 June 2018 Along’s excellent third album, Frances Quinlan clearly put in the time to sharpen her storytelling and own the idiosyncrasies of her voice. Billboard Staff, Billboard, "The 50 Best Albums of 2018 (So Far): Critics' Picks," 5 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'idiosyncrasy.' 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 idiosyncrasy

1604, in the meaning defined at sense 1a

History and Etymology for idiosyncrasy

Greek idiosynkrasia, from idio- + synkerannynai to blend, from syn- + kerannynai to mingle, mix — more at crater

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Statistics for idiosyncrasy

Last Updated

4 Dec 2018

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Time Traveler for idiosyncrasy

The first known use of idiosyncrasy was in 1604

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More Definitions for idiosyncrasy



English Language Learners Definition of idiosyncrasy

: an unusual way in which a particular person behaves or thinks

: an unusual part or feature of something


id·​i·​o·​syn·​cra·​sy | \ˌi-dē-ə-ˈsiŋ-krə-sē \
plural idiosyncrasies

Kids Definition of idiosyncrasy

: an unusual way of behaving or thinking that is characteristic of a person When you know someone a long time, you become accustomed to their idiosyncrasies— Lemony Snicket, The Ersatz Elevator


id·​io·​syn·​cra·​sy | \ˌid-ē-ə-ˈsiŋ-krə-sē \
plural idiosyncrasies

Medical Definition of idiosyncrasy 

1 : a peculiarity of physical or mental constitution or temperament

2 : individual hypersensitiveness (as to a drug or food) anemia accompanying the use of a sulfa drug is usually considered to be due to idiosyncrasy

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