The Collaborative International Dictionary of English v.0.48:

Chimera \Chime"ra\, n.; pl. Chimeras. [L. chimaera a chimera
   (in sense 1), Gr. ? a she-goat, a chimera, fr. ? he-goat; cf.
   Icel. qymbr a yearling ewe.]
   1. (Myth.) A monster represented as vomiting flames, and as
      having the head of a lion, the body of a goat, and the
      tail of a dragon. "Dire chimeras and enchanted isles."
      --Milton.
      [1913 Webster]

   2. A vain, foolish, or incongruous fancy, or creature of the
      imagination; as, the chimera of an author. --Burke.
      [1913 Webster]