objection
Claim of foul lodged by rider, patrol judge or other official after the running of a race. If lodged by official, it is called an inquiry.
odds-on
Odds of less than even money.
off side
Right side of horse.
off-track betting
Wagering at legalized betting outlets usually run by the tracks, management companies specializing in parimutuel wagering, or, in New York State, by independent corporations chartered by the state. Wagers at OTB sites are usually commingled with on-track betting pools.
official
1) Notice displayed when a race result is confirmed. 2) Used to denote a racing official.
on the bit
When a horse is eager to run. Also known as “in the bridle.”