Source : Webster's Revised Unabridged Dictionary (1913)

Trotter \Trot"ter\, n.
   1. One that trots; especially, a horse trained to be driven
      in trotting matches.

   2. The foot of an animal, especially that of a sheep; also,
      humorously, the human foot.

Source : WordNet®

trotter
     n 1: foot of a pig or sheep especially one used as food
     2: a horse trained to trot; especially a horse trained for
        harness racing [syn: {trotting horse}]