: an object in outer space that develops a long, bright tail when it passes near the sun
Full 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
: a small bright heavenly body that develops a cloudy tail as it moves in an orbit around the sun
Word History of 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.