idiosyncrasy

American  

[id-ee-uh-sing-kruh-see, -sin-] / ˌɪd i əˈsɪŋ krə si, -ˈsɪn- /

noun

• idiosyncrasies
  plural

1. a characteristic, habit, mannerism, or the like, that is peculiar to an individual.

   Synonyms:

   quirk, peculiarity

2. the physical constitution peculiar to an individual.

3. a peculiarity of the physical or the mental constitution, especially susceptibility toward drugs, food, etc.

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idiosyncrasy British  

/ ˌɪdɪəʊˈsɪŋkrəsɪ /

noun

1. a tendency, type of behaviour, mannerism, etc, of a specific person; quirk

2. the composite physical or psychological make-up of a specific person

3. an abnormal reaction of an individual to specific foods, drugs, or other agents

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Synonym Usage

See eccentricity.

Other Word Forms

Derived Forms

• idiosyncratic
  adjective

Inflected Forms

Nouns

• idiosyncrasies
  plural

Etymology

Origin of idiosyncrasy

First recorded in 1595–1605; from Greek idiosynkrāsía, equivalent to idio- idio- + syn- syn- + krâs(is) “a blending” + -ia -y ³

Explanation

If a person has an idiosyncrasy, he or she has a little quirk, or a funny behavior, that makes him or her different. If you only say goodbye in French, never in English, that would be an idiosyncrasy. Idio seems like it means stupid, but really it is Latin for "one's own," as an idiosyncrasy is one's own particular, usually odd, behavior. Putting salt in your hot chocolate or needing the light on to sleep or tapping your head while you think are all idiosyncrasies. A machine such as a DVD player has an idiosyncrasy if you have to do something weird to it to make it work like having to bang it on the back left-hand side to stop it from skipping.

Example Sentences

See Examples For:

idiosyncrasy idiosyncrasies

Indeed, the very features that make gifts inefficient as market transactions—surprise, idiosyncrasy, miscalibration—are often what make them meaningful as social gestures.

From The Wall Street Journal ● Dec. 23, 2025

“But we mixed that with a more Latin American idiosyncrasy, so it’s familiar but very different.”

From Los Angeles Times ● Nov. 21, 2025

The headline proposal of the reforms is the removal of the not proven verdict - a legal idiosyncrasy that can be traced back to the 17th Century.

From BBC ● Sep. 15, 2025

And “country,” the hands-down favorite music of “real Americans,” has long been a production-line item with as much idiosyncrasy in the songs as Olive Garden breadsticks.

From Salon ● Aug. 9, 2025

The results never completely caught on—but they endure as a historical curiosity of some idiosyncrasy.

From "Words Like Loaded Pistols" by Sam Leith

There’s no better way to quickly learn a person’s idiosyncrasies than living with them.

From Los Angeles Times ● Aug. 25, 2026

The primary race is asymmetrical because of the idiosyncrasies of Massie and the district he represents, according to T.J.

From Salon ● May 14, 2026

Kate Mayne, who is a farmer and the chair of NFU Shropshire, worked closely with the project and said that "local idiosyncrasies... are really important to us as farmers".

From BBC ● Apr. 27, 2026

And that might get personal: the astronauts laughed when asked what idiosyncrasies they feared their crewmates might discover.

From Barron's ● Mar. 27, 2026

These examples illustrate the broad range of questions concerning cultural idiosyncrasies, unrelated to environment and initially of little significance, that might evolve into influential and long-lasting cultural features.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Related Words

• eccentricity
• mannerism
• peculiarity
• trait