comet

noun

com·​et ˈkä-mət 

: a celestial body that appears as a fuzzy head usually surrounding a bright nucleus, that has a usually highly eccentric orbit, that consists primarily of ice and dust, and that often develops one or more long tails when near the sun

cometary

ˈkä-mə-ˌter-ē 

adjective

cometic

kə-ˈme-tik 

kä-

adjective

Examples of comet in a Sentence

Recent Examples on the Web

However, the planetesimals that did not form into the Jovian planets were left to travel through the solar system as comets. —Adam Lark, The Conversation, 16 June 2026

This would also challenge recent speculation that Eilmer understood the periodicity of Halley’s comet centuries before the late 17th century astronomer Edmund Halley. —Jennifer Ouellette, ArsTechnica, 14 June 2026

Astronomers have discovered three comets from other stars passing by the sun in recent years, and there should be an observable number of meteoroids burning up in our atmosphere from other stars systems as well. —Phil Plait, Scientific American, 12 June 2026

Giotto managed to send home both dramatic images of the comet’s nucleus and measurements of the cloud of material around it. —Quanta Magazine, 12 June 2026

Word History

Etymology

Middle English comete, from Old English cometa, from Latin, from Greek komētēs, literally, long-haired, from koman to wear long hair, from komē hair

First Known Use

before the 12th century, in the meaning defined above

Rhymes for comet

• grommet
• vomit
• recommit

Kids Definition

comet

noun

com·​et ˈkäm-ət 

: a bright heavenly body that develops a cloudy tail as it moves closer to the sun in its orbit

Etymology

Old English cometa "comet," from Latin cometa (same meaning), from Greek komētēs, literally, "long-haired," derived from komē "hair" — related to coma entry 2