English▸ adjective [attributive] consisting of four parts or elements:
a quadruple murder.
▪ consisting of four times as much or as many as usual:
a quadruple vodka.
▪ (of time in music) having four beats in a bar.
▸ verb increase or be increased fourfold:
[no object] oil prices quadrupled in the 1970s.
▸ noun a quadruple thing, number, or amount.
– ORIGIN late Middle English (as a verb): via French from Latin quadruplus, from quadru- ‘four’ + -plus as in duplus (see duple).