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

Adding to the clearer picture painted of this giant comet by ALMA was the first detection of molecular outgassing for C/2014 UN271. —Robert Lea, Space.com, 19 June 2025

The sky images can be stitched together to show changes in the cosmos, such as the movements of comets through the solar system. —Stephanie Pappas, Scientific American, 16 June 2025

And billions of years ago, icy comets and soggy asteroids delivered that water molecule—and so many more like it—to a young world named Earth. —Robin George Andrews, Smithsonian Magazine, 30 May 2025

Fish dart below, leaving glowing trails like comets. —Alexandra Gillespie, Outside Online, 28 Apr. 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