Although triple and treble share the meaning of "threefold," "consisting of three parts," "thrice multiplied," treble is rarely used except for its special sense in music: "having the highest range or part" (young choir boys with treble voices). One might say "You can triple your income this year," although treble could be correctly substituted for triple. As a verb, adjective, and noun, triple is used in sentences such as these: "He tripled his planting of vegetables that spring." "This play has triple implications." "In the third inning, the player hit a triple." "A rare occurrence in baseball is a triple play." Words or phrases of which triple forms a part include "triple time," "triple threat," "Triple Alliance," "triple measure," "Triple Entente," "triple rhyme," and "triple-decker."
Dictionary of problem words and expressions. Harry Shaw. 1975.