Emily Dickinson Lexicon

CEN'TAUR, n. [L. centaurus; Gr. κενταυρος. Qu. κεντεω, to spur, and ταυρος, a bull.]

1. In mythology, a fabulous being, supposed to be half man and half horse. It has been supposed that this fancied monster originated among the Lapithæ, a tribe in Thessaly, who first invented the art of breaking horses. But the origin of the fable and of the name is doubtful.
2. Part of a southern constellation, in form of a centaur, usually joined with the wolf, containing thirty-five stars; the Archer. – Encyc.