trail off
Used to describe a fit horse losing its competitive edge.
trial
In Thoroughbred racing, a preparatory race created in tandem with a subsequent, more important stakes race to be run a few days or weeks hence The Derby Trial.
trifecta
A wager picking the first three finishers in exact order. Called a “triactor” in Canada and a “triple” in some parts of the U.S.
trifecta box
A trifecta wager in which all possible combinations using a given number of horses are bet upon. The total number of combinations can be calculated according to the formula x3-3×2+2x, where x equals the amount of horses in the box. The sum of the formula is then multiplied by the amount wagered on each combination.
trot
A gait in which the legs of the horse move in diagonal pairs.
underlay
A horse racing at shorter odds than seems warranted by its past performances.