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

This vast misshapen island was traditionally noted for ghosts, folktales, eccentricity, fish, and friendliness. — Paul Theroux, Condé Nast Traveler, 22 Sep. 2026

Voorhees’ 19th century eccentricities stretched to the installation of beehives in the attic, but the space is now a cozy two-bedroom layout, with a living room and improved versions of the original porthole windows. — Richard Lane, Des Moines Register, 21 Sep. 2026

Its moribund eccentricities cannot be separated from the tenderness of its story because Rhys and co-writer and composer, Joss Holden-Rea, have taken the time to sculpt characters with interiority that feels invitational. — Zachary Lee, IndieWire, 16 Sep. 2026

Joe Griffin’s sound design and Sarah Riffle’s lighting contribute to the ethereal atmosphere, while Jazmin Aurora Medina’s costumes encompass the eccentricities and menace of the strange creatures the children meet on their travels. — Emily McClanathan, Chicago Tribune, 15 Sep. 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