Quadruple means to multiply something by four, making it four times as large. If you have three dollars and quadruple your money, you end up with twelve dollars. If a recipe calls for two cups of flour but you need to make four times as much, you quadruple the recipe to eight cups.

When used as an adjective, quadruple describes something with four parts or layers. Olympic figure skaters sometimes attempt the legendary quadruple jump, spinning four full rotations in the air before landing, a feat so difficult that only a handful of skaters have ever landed one in competition.

You can also use quadruple as a noun to mean a group of four or something four times as large as another. Quadruplets (four babies born together) get their name from this same root.