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

Astronomers theorize that 2003 EH1, which takes about 5 ½ years to orbit the sun, is a dead comet that is now essentially a rock. —Eric Lagatta, USA Today, 2 Jan. 2026

Because this comet will move between Earth and the sun, its tail will reflect and scatter a lot of sunlight in the direction of Earth — and into the eyes of observers — in late April 2026. —Jamie Carter, Space.com, 2 Jan. 2026

Unlike other meteor showers, which tend to be caused by debris falling from comets, the Quadrantids are produced by an asteroid, 2003 EH1. —Claire Cameron, Scientific American, 1 Jan. 2026

The comet is thought to have been ejected from a giant exoplanet and traversed the Milky Way for billions of years. —Devika Rao, TheWeek, 31 Dec. 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