Equus caballus, horse - solid-hoofed herbivorous quadruped domesticated since prehistoric times

thoroughbred - a racehorse belonging to a breed that originated from a cross between Arabian stallions and English mares

pony - an informal term for a racehorse; "he liked to bet on the ponies"

yearling - a racehorse considered one year old until the second Jan. 1 following its birth

dark horse - a racehorse about which little is known

mudder - a racehorse that runs well on a muddy racetrack

nonstarter - a horse that fails to run in a race for which it has been entered

pacer, pacesetter, pacemaker - a horse used to set the pace in racing

trotting horse, trotter - a horse trained to trot; especially a horse trained for harness racing