idiosyncrasy

noun

id·​i·​o·​syn·​cra·​sy ˌi-dē-ə-ˈsiŋ-krə-sē 

plural idiosyncrasies

1

a

: 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

idiosyncratic

ˌi-dē-ō-(ˌ)sin-ˈkra-tik 

adjective

idiosyncratically

ˌi-dē-ō-(ˌ)sin-ˈkra-ti-k(ə-)lē 

adverb

Synonyms

• crotchet
• curiosity
• eccentricity
• erraticism
• individualism
• kink
• mannerism
• oddity
• peculiarity
• quiddity
• quip
• quirk
• singularity
• tic
• trick
• twist

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 idiosyncrasies.

Recent Examples on the Web

Not to mention having to get used to the travel idiosyncrasies of another person. —Olivia Morelli, Condé Nast Traveler, 2 Sep. 2024

Add in the extra idiosyncrasies that generative AI systems can hallucinate into existence and you’re often left with an almost-but-not-quite-there picture of what happened. —Boone Ashworth, WIRED, 28 Aug. 2024

The Financial Times also reported on the mysterious Apex, noting idiosyncrasies in the company’s press release. —Bruce Gil, Quartz, 31 July 2024

From tiny, barely visible lines and dots to serif and non-serif typography, from depth ratings in meters vs. feet to crown guards that look like avian beaks, the world of vintage Rolex is positively filled with quirky idiosyncrasies that can be difficult to parse, let alone memorize. —Oren Hartov, Robb Report, 4 July 2024

Word History

Etymology

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

First Known Use

1604, in the meaning defined at sense 1a

Kids Definition

idiosyncrasy

noun

id·​io·​syn·​cra·​sy

ˌid-ē-ə-ˈsiŋ-krə-sē

plural idiosyncrasies

: a way of behaving or thinking that is characteristic of a person

idiosyncratic

ˌid-ē-ō-(ˌ)sin-ˈkrat-ik

adjective

idiosyncratically

-ˈkrat-i-k(ə-)lē

adverb

Medical Definition

idiosyncrasy

noun

id·​io·​syn·​cra·​sy ˌid-ē-ə-ˈsiŋ-krə-sē 

plural idiosyncrasies

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