The Collaborative International Dictionary of English v.0.48:

Homing \Hom"ing\ (h[=o]m"[i^]ng), p. a.
   Home-returning; -- used specifically of carrier pigeons.
   [1913 Webster]

   Homing pigeon, any pigeon trained to return home from a
      distance. Also called carrier pigeon. Most are bred from
      the domestic pigeon Columba livia. Homing pigeons are
      used for sending back messages or for flying races. By
      carrying the birds away and releasing them at gradually
      increasing distances from home, they may be trained to
      return with more or less certainty and promptness from
      distances up to four or five hundred miles. The birds
      typically do not stop on their way home, and may average
      as much as 60 miles per hour on their return trip. If the
      distance is increased much beyond 400 miles, the birds are
      unable to cover it without stopping for a prolonged rest,
      and their return becomes doubtful. The record for returnig
      from a distance is close to 1,200 miles. Homing pigeons
      are not bred for fancy points or special colors, but for
      strength, speed, endurance, and intelligence or homing
      instinct. Although used since ancient times, homing
      pigeons have been largely displaced for practical purposes
      by radio and electronic communications, but they are still
      used in some special situations at the end of the 20th
      century. They were used in military operations as recently
      as in World War II.
      [Webster 1913 Suppl. +PJC] hominian

WordNet (r) 3.0 (2006):

homing pigeon
    n 1: pigeon trained to return home [syn: homing pigeon,
         homer]

Moby Thesaurus II by Grady Ward, 1.0:

53 Moby Thesaurus words for "homing pigeon":
   Aquarius, Ganymede, Hebe, bearer, bheesty, busboy, caddie,
   cargo handler, carrier, carrier pigeon, carter, common carrier,
   conveyer, coolie, cupbearer, drayman, express, expressman,
   freighter, gun bearer, hauler, homer, letter carrier,
   litter-bearer, mail car, mail coach, mail packet, mail train,
   mail truck, mailer, mailplane, packet boat, pigeon post, porter,
   post boat, post car, post coach, post-horse, post-office car,
   poster, railway mail car, redcap, shield-bearer, skycap, stevedore,
   stretcher-bearer, the Water Bearer, transporter, truck driver,
   trucker, wagoner, water boy, water carrier