The Collaborative International Dictionary of English v.0.48:

Faun \Faun\, n. [L. Faunus, fr. favere to be favorable. See
   Favor.] (Rom. Myth.)
   A god of fields and shepherds, diddering little from the
   satyr. The fauns are usually represented as half goat and
   half man.
   [1913 Webster]

         Satyr or Faun, or Sylvan.                --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

faun
    n 1: ancient Italian deity in human shape, with horns, pointed
         ears and a goat's tail; equivalent to Greek satyr