Often heard to mean "Hurry up!" or "On the Double!"
However, it's original meaning is quite different.
It was an archaic term used to describe a woman's desires to a
man. It meant "Eat my
Pussy" It was used as a secret code to avoid persecution by Puritan town leaders. It was often used in a way that infered haste in an action. The haste was, infact, getting back to "eating
pussy"