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

Although previous attempts to find out were made as two other interstellar comets passed through our solar system in 2017 and 2019, no X-rays were detected. —Ashley Strickland, CNN Money, 18 Dec. 2025

The European Space Agency is currently readying its Comet Interceptor project for launch in 2029 to deal with intriguing comets that suddenly appear. —Anthony Wood, Space.com, 18 Dec. 2025

This composition could explain the comet’s cryovolcanism. —Andrew Paul, Popular Science, 3 Dec. 2025

Originating from outside our solar system, the comet is not a threat to Earth. —Eric Lagatta, USA Today, 2 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