A set or group of three people, objects, or related things. The dessert was served as a triple of mini pastries on one plate.
A hit in baseball that allows the batter to reach third base. He hit a triple in the last inning, bringing two runners home.
A drink containing three measures of alcohol. She ordered a triple to celebrate her promotion.
Mathematics: an ordered set of three elements. The ordered triple (2, 3, 5) satisfies the equation.