Comet
Pronunciation : Com"et
Part of Speech : n.
Etymology : [L. cometes, cometa, from Gr. coma: cf. F. com?te.] (Astron.)
Definition : Defn: 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.
Source : Webster's Unabridged Dictionary, 1913