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

From charting the Milky Way with unprecedented precision to landing a probe on a comet hurtling through space, ESA has built a legacy defined by curiosity and collaboration. —Kenna Hughes-Castleberry, Space.com, 17 Feb. 2026

Robotic probes proved increasingly versatile and successful, eventually visiting every planet in the solar system as well as a scattering of moons, comets, and asteroids. —New Atlas, 15 Feb. 2026

The comet will reach perihelion, its closest point to the sun in its orbit, on April 4, per Sky & Telescope. —Jenna Prestininzi, Freep.com, 13 Feb. 2026

Gas from nebulas as well as water from comets and asteroids may have also been a source of Earth’s hydrogen, Hirose added. —Mindy Weisberger, CNN Money, 10 Feb. 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