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

Since sources of spray were likely common on the early Earth, Zare thinks this process could produce far more organic chemicals than potential alternatives like lightning strikes, hydrothermal vents, or impacting comets. —Ars Technica, 14 Mar. 2025

As these stars and planets whirl around each other, their gravitational interactions perturb the orbits of other smaller objects in Alpha Centauri, ranging from asteroids and comets — planetesimals left over from the formation of our neighboring system — to particles of dust. —Robert Lea, Space.com, 5 Mar. 2025

Cataclysmic collisions with protoplanets, asteroids and comets are thought to be common during a planet’s formation and for the next tens to hundreds of millions of years thereafter. —Conor Feehly, Scientific American, 4 Mar. 2025

Stevns Klint provides one of the most complete and accessible records of this event, with layers containing evidence of the impact of a massive asteroid or comet, which is believed to have triggered the extinction event. —Jonathan Granoff, Newsweek, 29 Jan. 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