adj., n., & v.
adj. 1 fourfold. 2 a having four parts. b involving four participants (quadruple alliance). 3 being four times as many or as much. 4 (of time in music) having four beats in a bar.
n. a fourfold number or amount.
v.tr. & intr. multiply by four; increase fourfold. quadruply adv.
[ F f. L quadruplus (as QUADRI-, -plus as in duplus DUPLE) ]