Definition of comet in English:



  • A celestial object consisting of a nucleus of ice and dust and, when near the sun, a ‘tail’ of gas and dust particles pointing away from the sun.

    • ‘Sometimes, the stresses are strong enough to break off chunks of the comet's nucleus.’
    • ‘Some explanations for extinctions and evolution include strikes by asteroids or comets.’
    • ‘There are vast numbers of comets in the solar system, more than there are asteroids, but most lie out of sight beyond Pluto.’
    • ‘As orbiting comets pass near the sun, intense heat strips them of a layer of dust and ice.’
    • ‘Bombardment by asteroids and comets is an extraterrestrial process that may release huge quantities of water.’
    • ‘In particular he showed that comets have a solid nucleus, and that they generate their own light.’
    • ‘We have just discussed some of the positive benefits of planetary impact by comets and asteroids.’
    • ‘Several bright comets streaked across the sky and then disappeared in an instant.’
    • ‘The spacecraft's point of view now captures the shadowed side of the comet's nucleus.’
    • ‘The Hawaii researchers observed the comet on July 17 and July 18 and discovered many more fragments.’
    • ‘He observed the comets of 1665, and made other astronomical observations, publishing his descriptions of these events.’
    • ‘Rather, they are produced by bits of dusty debris shed by orbiting comets and asteroids.’
    • ‘Dozens of comets are discovered each year as well, many by automated telescopes and spacecraft.’
    • ‘A bright comet is a spectacular astronomical event.’
    • ‘Warming from the sun causes frozen organic compounds on a comet's surface to sublime, or vaporize.’
    • ‘The spacecraft will orbit the comet's nucleus.’
    • ‘He saw a comet passing far, far away in the distance from where he made his steps.’
    • ‘A bright comet had appeared on 14 November 1680.’
    • ‘She discovered eight comets, a record by a female astronomer until 1987.’
    • ‘A comet is discovered and as it comes closer to earth, it becomes apparent it may strike our planet.’


Late Old English, from Latin cometa, from Greek komētēs ‘long-haired (star)’, from komē ‘hair’; reinforced by Old French comete.