The Collaborative International Dictionary of English v.0.48:

Horny \Horn"y\, a. [Compar. Hornier; superl. Horniest.]
   1. Having horns or hornlike projections. --Gay.
      [1913 Webster]

   2. Composed or made of horn, or of a substance resembling
      horn; of the nature of horn. "The horny . . . coat of the
      eye." --Ray.
      [1913 Webster]

   3. Hard; callous. "His horny fist." --Dryden.
      [1913 Webster]