Because I'm on a slang roll, here are some fun terms you might hear on the racetrack.
Backstretch - refers to both the side of the racehorse away from the grandstands and to the track stables. Backside is also sometimes used for the stables.
Front stretch - the side of the racehorse next to the grandstands.
Blue Light Special - a horse that the owner paid next to nothing for that turns out to be a stakes winner.
Black type - a stakes winner or placed horse in a horse's pedigree.
Pony - a horse used to lead a racehorse to the start (US only - other countries expect the racehorses to go to the start on their own)
Nickel-bred - poorly bred or common.
Sprinter - a horse that prefers shorter distances
Router - a horse that prefers longer distances
Furlong - an eighth of a mile, commonly used to measure horse races
Place - to come second
Show - to come third
Across the board - a bet on a horse to win, place, or show
Added money - a purse is normally made up out of the money paid in entry fees. If somebody donates more money, it's "added money."
Allowance - a race with certain conditions. Most races are allowances.
Apprentice - a novice or inexperienced jockey.
Bug - a slang term for an apprentice
Baby race - a race for two-year-olds
Bat - whip (also used by stadium jumpers)
Breakdown - a potentially career-ending injury. The horse "broke down in training."
Claiming - in a claiming race, all of the entries are for sale at a designated price.
Distaff - a female horse
Flat race - any race with no jumps in it, as opposed to steeplechase or hurdle races
Maiden - a horse that has never won a race
Prep race - a race a horse is entered into not with the plan of winning, but to ensure fitness for a different race.
Silks - the colorful jacket and cap worn by jockeys
Shedrow - the stable area
Sloppy - muddy
And that's just a few of them - the racing industry has its own entire language.