Definition of triple crowns:
(n) :
(sports) An award representing victory in three events, especially in horse-racing.
(n) :
The three-tiered tiara formerly worn by Popes.
(n) :
(baseball) The feat of leading one's league in three key statistical categories—batting average, home runs, and RBI for hitters; wins, strikeouts, and ERA for pitchers
(n) :
(horse racing, US) The three greatest thoroughbred races of the year restricted to three-year-olds: the Kentucky Derby, Preakness Stakes, and Belmont Stakes
(n) :
(horse racing, UK) The three greatest thoroughbred races of the year restricted to three-year-olds: the 2,000 Guineas Stakes, Derby Stakes (aka "Epsom Derby"), and St. Leger Stakes
(n) :
(horse racing, Canada) The three greatest thoroughbred races of the year restricted to three-year-olds: the Queen's Plate, Prince of Wales Stakes, and Breeders' Stakes