Webster’s Revised Unabridged Dictionary · 1913
Double-quick
Dou′ble-quick′, a. (Mil.) Of, or performed in, the fastest time or step in marching, next to the run; as, a double-quick step or march.
Dou′ble-quick′, n. Double-quick time, step, or march.
☞ Double-quick time requires 165 steps, each 33 inches in length, to be taken in one minute. The number of steps may be increased up to 180 per minute.
Dou′ble-quick′, v. i. & t. (Mil.) To move, or cause to move, in double-quick time.