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.

---

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

---

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

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

No idiosyncrasy is too singular for him to wrestle into submission – and over three seasons of the Syfy series, he’s bear-hugged a lot of them.

From Salon ● Mar. 28, 2024

At times the latter has been in strict alignment with hip-hop’s center; sometimes it has taken her to pop excess; at other moments, it has found her pursuing a path of rap idiosyncrasy.

From New York Times ● Dec. 11, 2023

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

From "Words Like Loaded Pistols" by Sam Leith

He portrays Mr. David, for all the comedian’s considerable idiosyncrasies, as an indisputable comic genius, a doting father and a loyal friend.

From The Wall Street Journal ● Oct. 9, 2026

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

She’d always pull back enough in her interactions with her classmates to give herself room to quietly observe them, so that when she got home she could practice imitating their accents, their idiosyncrasies, their style.

From "The Other Wes Moore: One Name, Two Fates" by Wes Moore

Related Words

• eccentricity
• mannerism
• peculiarity
• trait