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

They can be seen each year when the Earth passes through a denser clump of the comet’s debris during its orbit around the sun, Thompson said. — Iris Kwok, Los Angeles Times, 5 Nov. 2026

Scientists believe comet Encke was part of a larger body that broke up roughly 20,000 years ago, creating the complex responsible for the Southern and Northern Taurids, as well as at least three other meteor showers. — Dharma Niles, CNN Money, 4 Nov. 2026

Most recently, the telescope was instrumental in documenting comet 3I/ATLAS, the third interstellar object ever detected passing through the solar system. — Andrew Paul, Popular Science, 2 Nov. 2026

Using the James Webb Space Telescope (JWST), scientists have found that the interstellar comet 3I/ATLAS was built from tiny grains of ice mixed with dust that are quite different from the solar system’s comets. — Keith Cooper, Space.com, 2 Nov. 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