double time

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A marching pace of 180 three-foot steps per minute.
• noun A rate of pay, as for overtime work, that is twice the regular rate.

from The Century Dictionary.

• noun Milit., same as double-quick.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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
• noun 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
• noun dance A dance step pattern with six steps
• noun A rate of pay twice that of normal

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a doubled wage (for working overtime)
• adverb at a faster speed
• noun a fast marching pace (180 steps/min) or slow jog