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

• 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

Even the film’s eccentricities that do feel out of a Pynchon novel — notably Lockjaw’s desire to join a secret society of white supremacists called the Christmas Adventurers Club — read as plausible in the current political climate. —Andrew McGowan, Variety, 26 Sep. 2025

But in Franz, Kafka is pretty resolute in his identity and his eccentricities, notably in his insistence on writing all his now-famous literary works by hand. —Damon Wise, Deadline, 25 Sep. 2025

The glitch smoothed out the eccentricities of texture in the image and cast a dusky halo around every shape. —Zachary Fine, New Yorker, 23 Sep. 2025

In This is Spinal Tap fashion, DiBergi captures the band’s eccentricities and penchant for attracting bad luck at every turn. —Tim Lammers, Forbes.com, 13 Sep. 2025

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