A: Let’s shake a leg, you guys. We need to be there in 20 minutes.

    B: Take it easy. It’s not rush hour and we will get there on time.

    Note: This idiom means to “hurry, move faster.” It’s often used as a command. It comes from the American Civil War. The battles were bloody and gruesome. Often after a bayonet charge, the dead and wounded would end up in a tangled and bloody pile. When the fighting ended, the stretcher-bearers would come out to sort the dead from the wounded. One way they had to sort out those still living was to lift a leg or an arm and jostle it. Sometimes a soldier would move one of his arms or legs to indicate that he was alive. After a time, the stretcher-bearers would first yell to the piles of bodies “shake a leg or arm” as they approached. The shortened “shake a leg” began to be used in any situation where one wanted to rouse someone to action.