com·​et ˈkä-mət How to pronounce comet (audio)
: 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 adjective
cometic adjective

Examples of comet in a Sentence

Recent Examples on the Web Relatively bright, currently visible comets appear in the S50's database, as mentioned. PCMAG, 16 May 2024 Along with their diabetic son Nathan, the couple were forced to flee in the first film as a comet hurtled towards earth, threatening to destroy the planet. K.j. Yossman, Variety, 9 May 2024 See all Example Sentences for comet 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'comet.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Time Traveler
The first known use of comet was before the 12th century

Dictionary Entries Near comet

Cite this Entry

“Comet.” Dictionary, Merriam-Webster, Accessed 20 May. 2024.

Kids Definition


com·​et ˈkäm-ət How to pronounce comet (audio)
: a bright heavenly body that develops a cloudy tail as it moves closer to the sun in its orbit

Old English cometa "comet," from Latin cometa (same meaning), from Greek komētēs, literally, "long-haired," derived from komē "hair" — related to coma entry 2

More from Merriam-Webster on comet

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