Quadruple

For international treaties with the name, see Quadruple Alliance

In mathematics, a quadruple or quadruplet is an n-tuple with n being 4. This means it depicts four elements, with the order of the elements carrying meaning. This differs from a set, where the order of the elements is meaningless and where no element could exist more than once. Derived from this abstract meaning, it is used in several other contexts including: In football, The Quadruple is the act of winning four top tier trophies in one season.
To quadruple a magnitude is to multiply it by 4.
Quadruplets are four children born in one pregnancy. See Multiple birth.
A quadruplet is a type of note in music (see tuplet).
A redundant backup system that has three secondary systems to take over if the primary fails. (see RAID 1)
A figure skating jump with four revolutions.