Asteroid \As"ter*oid\, n. [Gr. ? starlike, starry; 'asth`r star + ? form: cf. F. ast['e]ro["i]de. See Aster.]

A starlike body; esp. one of the numerous small planets whose orbits lie between those of Mars and Jupiter; -- called also planetoids and minor planets.

Source: Webster's Revised Unabridged Dictionary (1913)