Definition of comet
: 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
cometaryplay \ˈkä-mə-ˌter-ē\ adjective
cometicplay \kə-ˈme-tik, kä-\ adjective
Recent Examples of comet from the Web
The comet is best seen after 10 p.m. local time, when the sky gets truly dark.
Scientists believe that the solar wind gives comets their tails.
Parker, who was working at the University of Chicago’s Enrico Fermi Institute at the time, came up with the concept while trying to explain why comet tails always point away from the sun.
View a great naked-eye comet, an opportunity which occurs only a few times per century.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'comet'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of comet
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 12th century
COMET Defined for English Language Learners
Definition of comet for English Language Learners
: an object in outer space that develops a long, bright tail when it passes near the sun
COMET Defined for Kids
Definition of comet for Students
: a small bright heavenly body that develops a cloudy tail as it moves in an orbit around the sun
History for comet
The tail of a comet looks rather like long hair streaming behind the head. The ancient Greeks named comets with the word komētēs, which means literally “long-haired.” This word comes from the noun komē, “hair on one's head” or “shock of hair.” The English word comet came from the Greek name for comets.
Seen and Heard
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