whale
n.— «In horseplaying parlance, Maury Wolff is a whale, one of the thousand or so professional bettors who collectively wager as much as $1.5 billion a year on thoroughbred races in the United States. He will not attend the Kentucky Derby at Churchill Downs on Saturday. In fact, he and the other whales rarely set foot in a racetrack.» —“Horse Racing’s Biggest Bettors Are Reaping Richest Rewards” by Joe Drape New York Times Apr. 26, 2004. (source: Double-Tongued Dictionary)