IN FOAL – a pregnant mare
IN THE MONEY – finishing first, second or third
IN HAND – running under moderate control, at less than best pace
IMPOST – weight carried or assigned
INQUIRY – stewards or judges reviewing the race to check into a possible infraction of the rules
IRONS – stirrups
JAIL – refers to the first month a claimed horse is in a new barn whereby racing rules require it to be entered at a claiming price above that which it was claimed
JOCKEY – the person who rides a horse in a race
JOCKEY AGENT – one who secures riding assignments for a jockey in return for a percentage of the jockey’s earnings
JOCKEY FEE - sum paid to a rider.
JOG - slow, easy gait.
JUVENILE - a two-year-old horse.
LASIX - a medication for the treatment of bleeding.
LATE DOUBLE - a second daily double offered on the latter part of the program. (See Daily Double).
LEAD PONY - horse or pony who heads parade of field from paddock to starting gate. Also a horse or pony who accompanies a starter to post.
LEG UP - to help a jockey mount his horse.
LENGTH - length of a horse from nose to tail, about 8 feet. Also distance between horses in a race.
LOCK - slang for a "sure thing" winner.
LUG (in or out) - action of a tiring horse, bearing in or out.
LUNGE - horse rearing or plunging.
MAIDEN - a horse who has not won a race. Also applied to a non-winning rider.
MAIDEN RACE - a race for non-winners.
MARE - female horse 5 years old or older. Also, female of any age who has been bred.
MEDICATION LIST - a list kept by the track veterinarian and published by the track and Daily Racing Form.
MIDDLE DISTANCE - broadly; From one mile to less than a mile and an eighth.
MINUS POOL - a mutual pool caused when one horse is so heavily wagered on, that after deductions of state tax and commission, there is not enough money left to pay the legally prescribed minimum on each winning bet.
MORNING GLORY - a horse who performs well in morning workouts but fails to reproduce that form in races.
MORNING LINE - approximate odds quoted before wagering determines exact odds.
MUDDY TRACK - deep condition of racetrack after being soaked with water.
MUDDER - horse who races well on muddy tracks.