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

Impact craters are formed when an object from space such as a meteoroid, asteroid or comet strikes the Earth at a very high velocity. —Marian Selorm Sapah, Space.com, 2 Aug. 2025

Italian astronomer Giovanni Schiaparelli uncovered the comet as the source of the Perseids in 1865. —Jenna Prestininzi, Freep.com, 21 July 2025

Gemini North’s Multi-Object Spectrograph also reveals the comet’s compact coma — a cloud of gas and dust surrounding its icy nucleus. —Jamie Carter, Forbes.com, 16 July 2025

Set in 1997, the Hale-Bopp comet is passing by Earth, and teenager Maggie Campion has a secret. —Andreas Wiseman, Deadline, 9 July 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