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

Director Craig Gillespie — whose impressive filmography has included I Tonya, Lars & The Real Girl, Pam & Tommy and Cruella — has proved to be a master at letting characters breathe in all their eccentricity. — Pete Hammond, Deadline, 24 June 2026

The stylistic eccentricities have been dialed back, including the use of old Hollywood film clips to reflect the action and possibly the thoughts of its main character, a cinephile from space, who is both practicing and enacting the work of a private detective. — Robert Lloyd, Los Angeles Times, 19 June 2026

Designers embraced audacious concepts, leading to iconic cars like the Corvette and Thunderbird, alongside numerous eccentricities. — Peter Lyon, Forbes.com, 18 June 2026

The singers, both known for onstage personas and eccentricities, dated in 2019 and confirmed their split one year later. — Shania Russell, Entertainment Weekly, 15 June 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