noun a member of the solar system which usually moves in an elongated orbit, approaching very near to the sun in its perihelion, and receding to a very great distance from it at its aphelion. a comet commonly consists of three parts: the nucleus, the envelope, or coma, and the tail; but one or more of these parts is frequently wanting. ·see illustration in appendix.
COMET
Meaning of COMET in English
Webster English vocab. Английский словарь Webster. 2012