n. A horse racing track that also includes slot machines, video gambling terminals, or other casino features.
Here's how racinos work, and why fans, breeders, and track owners like the idea: Racetracks install slots, generally thousands at a time, on-site. Racing fans, presumably between races, spend a few dollars on the slots. The income made by the track, after sizable payouts to the state and the lottery system, is funneled back in the form of bigger purses for each race. The difference between a racino-funded purse and one without slot money can be as much as $ 175,000.
—Heather Timmons, “Can slot machines rescue racing?,” Business Week, December 02, 2002
1995 (earliest)
There's no place in the world where casinos and pari-mutuel racing have ever coexisted, but that doesn't mean we can't!" says Richard L. Duchossois, who poured $ 200 million of his own money into rebuilding Arlington Park, a palace of a racetrack outside Chicago, but who now expects to take a 35% hit in his handle this season. Last fall a giant floating casino called the Grand Victoria—with 977 slot machines, 39 blackjack tables, seven roulette wheels, eight craps tables and room enough for 1,736 people—opened for business on the Fox River in Elgin, just 12 miles from Arlington's front door.

Duchossois beseeched the state legislature for the right to open a casino, and he threatened to padlock his doors this year when it refused. He backed off that dime, but only after the state allowed him to cut his 1995 racing dates, and hence his losses, from 131 days to 55. Still hinting darkly that this might be Arlington's final year unless he can get relief to compete with the boat, Duchossois intends to continue his quest for a hybrid creation that he calls a racino. "Casino and racing can coexist," he says. "If "they can't, the racing and breeding industry is going to self-destruct.
—William Nack, “A house divided,” Sports Illustrated, July 10, 1995