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

Our experience tells us that the Solar System is full of hazardous comets and asteroids, periodically plunging into the inner reaches of our star’s vicinity. —Big Think, 26 Nov. 2025

The fractured comet is currently too dim to be seen by the naked eye, but can still be spotted with the aid of a small backyard telescope close to the stars of the famous Big Dipper asterism in the constellation Ursa Major, or captured in long exposure photography! —Anthony Wood, Space.com, 24 Nov. 2025

This image was taken on Sept 28, 2025- just days before the comet’s closest approach to Mars - by an instrument on NASA's MAVEN spacecraft, which has been studying Mars from orbit since 2014. —Jeffrey Kluger, Time, 20 Nov. 2025

This may seem hopeless at first blush; the next nearest star is 10,000 times farther away than Neptune, so even in this best-case scenario, any comets beyond our solar system would be impossibly faint. —Phil Plait, Scientific American, 20 Nov. 2025

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