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

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

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

Desserts are splendid, modern with need for the eccentricity of exotic herbs. —John Mariani, Forbes, 4 Oct. 2024

Something on a circular orbit has an eccentricity of 0. —Phil Plait, Scientific American, 27 Sep. 2024

The show follows Elsbeth, a quirky, colorful, and sharp attorney who is often underestimated because of her bubbly eccentricities. —Patricia Karounos, refinery29.com, 1 Oct. 2024

An object with an eccentricity greater than 0 but less than 1 has an elliptical orbit. —Phil Plait, Scientific American, 27 Sep. 2024

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

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