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

Ice-rich comets or drier asteroids are the two prime suspects. —Robin George Andrews, Scientific American, 7 Apr. 2026

During the few hours surrounding the time of the comet's closest approach to the sun, the comet was hidden behind the occulting disk, which also blocks the direct light of the sun. —Joe Rao, Space.com, 7 Apr. 2026

The telescope, known as the Near-Earth Object Surveyor, will detect infrared light or heat being emitted by elusive asteroids and comets. —N'dea Yancey-Bragg, USA Today, 4 Apr. 2026

Typically, comets evolve over centuries, but because of the comet's rotational shifts, the changes are happening faster. —Kerry Breen, CBS News, 27 Mar. 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