refuse
1) When a horse will not break from the gate. 2) In jumping races, balking at a jump.
reserve
A minimum price, set by the consignor, for a horse in a public auction. For example, “The horse did not reach its reserve.”
ridden out
A horse that finishes a race under mild urging, not as severe as driving.
ride short
Using short stirrups.
roan
A horse color where the majority of the coat of the horse is a mixture of red and white hairs or brown and white hairs. The mane, tail and legs may be black, chestnut or roan unless white markings are present. Starting with foals of 1993, the color classifications gray and roan were combined as “roan or gray.”
rogue
Ill-tempered horse.