Source : Webster's Revised Unabridged Dictionary (1913)

Quadruple \Quad"ru*ple\, a. [L. quadruplus, from quattuor four:
   cf. F. quadruple. See {Quadrate}, and cf. {Double}.]
   Fourfold; as, to make quadruple restitution; a quadruple
   alliance.

   {Quadruple time} (Mus.), that in which each measure is
      divided into four equal parts.

Source : WordNet®

quadruple time
     n : a time signature indicating four beats to the bar [syn: {common
         time}, {four-four time}, {common measure}]