Definition of "double time"

(military) A fast marching pace of 180 steps per minute, 36 inches in length for the Marine Corps and Navy, 30 inches in length for the Army. It is not really double the speed of quick time as quick time is 112-120 steps per minute.

(music) A musical rhythm twice as fast as the overall beat, with this pattern of note lengths: 3/16 3/16 1/4 3/16 3/16.  examples

(dance) A dance step pattern with six steps.  examples

A rate of pay that is twice the normal rate.  examples