BounceA poor race run directly following a career-best or near-best performance.
BoxA wagering term denoting a combination bet whereby all possible numeric combinations are covered.
Boxed (In)To be trapped between, behind or inside of other horses.
Brace (or Bracer)Rubdown liniment used on a horse after a race or workout.
Break (a horse)1) To train a young horse to wear a bridle and saddle, carry a rider and respond to a rider's commands. Almost always done when the horse is a yearling. 2) To leave from the starting gate.
Break MaidenHorse or rider winning the first race of its career. Also known as "earning a diploma."
BreakageIn parimutuel payoffs, which are rounded down to a nickel or dime, the pennies that are left over. Breakage may be used for any of a number of purposes, depending upon a state's rules of racing.
BreatherEasing off on a horse for a short distance in a race to permit it to conserve or renew its strength.
Bred1) A horse is considered to have been bred in the state or country of its birth -- Secretariat was a Virginia-bred. 2) The past tense of "breed."
BreederOwner of the dam at time of foaling unless the dam was under a lease or foal-sharing arrangement at the time of foaling. In that case, the person(s) specified by the terms of the agreement is (are) the breeder(s) of the foal.