Source : Webster's Revised Unabridged Dictionary (1913)
Comet \Com"et\, n. [L. cometes, cometa, from Gr. ? comet, prop.
long-haired, fr. ? to wear long hair, fr. ? hair, akin to L.
coma: cf. F. com[`e]te.] (Astron.)
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 : WordNet®
comet
n : (astronomy) a relatively small extraterrestrial body
consisting of a frozen mass that travels around the sun
in a highly elliptical orbit