Source : Webster's Revised Unabridged Dictionary (1913)

Simile \Simi"*le\, n.; pl. {Similes}. [L., from similis. See
   {Similar}.] (Rhet.)
   A word or phrase by which anything is likened, in one or more
   of its aspects, to something else; a similitude; a poetical
   or imaginative comparison.

         A good swift simile, but something currish. --Shak.

Source : WordNet®

simile
     n : a figure of speech that expresses a resemblance between
         things of different kinds (usually formed with `like' or
         `as')