quadruple (Adjective) — Having four units or components. ex. "quadruple rhythm has four beats per measure"
quadruple (Adjective) — Four times as great or many. ex. "a quadruple increase in the dosage"
quadruple (Noun) — A set of four similar things considered as a unit.
quadruple (Noun) — A quantity that is four times as great as another.
quadruple (Verb) — Increase fourfold. ex. "His stock earning quadrupled"