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

The observatory was named for fast-flying swift birds due to its ability to pivot rapidly to look at cosmic events and afterglows, enabling the study of comets, gravitational waves and black holes over long periods of time. — Ashley Strickland, CNN Money, 3 July 2026

In August, there’s also a comet that should be visible with small telescopes. — John Metcalfe, Mercury News, 3 July 2026

Last year, Loeb raised the possibility that the interstellar comet 3I/ATLAS could have alien origins. — CBS News, 1 July 2026

As of April 2025, astronomers have identified nearly 40,000 near-Earth objects, or NEOs – that is, asteroids and comets whose orbits bring them close to Earth – according to a report from NASA's Office of the Inspector General. — Briana Alvarado, ABC News, 30 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