Emily Dickinson Lexicon

CHI-ME'RA, n. [L. chimæra; Gr. χιμαιρα, a goat, a monstrous beast.]

1. In fabulous history, a monster with three heads, that of a lion, of a goat, and of a dragon, vomiting flames. The fore parts of the body were those of a lion, the middle was that of a goat, and the hinder parts were those of a dragon; supposed to represent a volcanic mountain in Lycia, whose top was the resort of lions, the middle, that of goats, and the foot, that of serpents. Hence,
2. In modern usage, a vain or idle fancy; a creature of the imagination, composed of contradictions or absurdities, that can have no existence except in thought. – Encyc.