eccentricity

noun

ec·​cen·​tric·​i·​ty ˌek-(ˌ)sen-ˈtri-sə-tē 

plural eccentricities

1

a

: the quality or state of being eccentric

b

: deviation from an established pattern or norm

especially : odd or whimsical behavior

2

a

: a mathematical constant that for a given conic section is the ratio of the distances from any point of the conic section to a focus and the corresponding directrix

b

: the eccentricity of an astronomical orbit used as a measure of its deviation from circularity

Synonyms of eccentricity

• characteristic
• trick
• trait
• idiosyncrasy
• mannerism
• quirk
• singularity
• peculiarity
• individualism
• curiosity
• oddity
• habit
• twist
• tic

Examples of eccentricity in a Sentence

Some people weren't very tolerant of his eccentricity.

Talking to her plants is one of her many eccentricities.

Recent Examples on the Web

With the exception of the central character played by Judy Greer, all the figures onscreen display the sort of eccentricities that are presumably meant to be either amusing or endearing but instead simply come across as odd. —Frank Scheck, HollywoodReporter, 14 Mar. 2026

Watch young John Early, Kate Berlant, and Cole Escola re-create a scene from the film in intricate detail and see camp interpretation at its finest — comedians using Showgirls’s eccentricities to unearth something delicious. —Jason P. Frank, Vulture, 12 Mar. 2026

Built in 1940 by architect Gerard Colcord, the home underwent a three-year renovation that preserved its bones while editing out the eccentricities left behind by former owners—including Cage’s tarantula room and Martin’s personal performance stage, as well as his outdoor pony corral. —Paige Reddinger, Robb Report, 7 Mar. 2026

Less massive objects tend to have rounder orbits, while the most massive, brown-dwarf-like of these objects vary more in their eccentricity. —Kiona N. Smith, Space.com, 2 Mar. 2026

Word History

Etymology

borrowed from Medieval Latin excentricitāt-, excentricitās, from ecentricus, excentricus "not having the earth exactly at its center, eccentric entry 1" + Latin -itāt-, -itās -ity

First Known Use

1545, in the meaning defined at sense 1a

Rhymes for eccentricity

• authenticity
• chromaticity
• concentricity
• domesticity
• elasticity
• electricity
• iconicity
• metallicity
• multiplicity
• specificity
• synchronicity
• analyticity

Kids Definition

eccentricity

noun

ec·​cen·​tric·​i·​ty ˌek-ˌsen-ˈtris-ət-ē 

plural eccentricities

1

a

: the quality or state of being eccentric

b

: something that does not follow an established pattern, norm, or rule

especially : unusual behavior

2

: the amount by which a nearly circular path is not circular

an orbit's eccentricity