The Collaborative International Dictionary of English v.0.48:

Trotter \Trot"ter\, n.
   1. One that trots; especially, a horse trained to be driven
      in trotting matches.
      [1913 Webster]

   2. The foot of an animal, especially that of a sheep; also,
      humorously, the human foot.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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, trotter]

Moby Thesaurus II by Grady Ward, 1.0:

89 Moby Thesaurus words for "trotter":
   ambler, ankle, arch, bacon, bayonet legs, bowlegs, butt, calf,
   chitterlings, clubfoot, cnemis, cob, cochon de lait, cracklings,
   digit, dog, drumstick, extremity, fat back, fetlock, flitch, foot,
   forefoot, foreleg, forepaw, gaited horse, galloper, gamb, gambrel,
   gammon, gigot, ham, ham steak, harefoot, haslet, headcheese, heel,
   high-stepper, hind leg, hock, hoof, instep, jamb, jambon,
   jambonneau, knee, lard, leg, limb, pacer, pad, padnag, pastern,
   patte, paw, pedal extremity, pedes, pes, picnic ham, pied,
   pieds de cochon, pig, podite, popliteal space, pork, porkpie,
   prancer, pug, racker, salt pork, scissor-legs, shank, shin,
   side of bacon, side-wheeler, single-footer, small ham, sole,
   sowbelly, splayfoot, stems, stepper, stumps, suckling pig, tarsus,
   toe, tootsy, trotters, ungula