hit the ground running

Finding yourself in a situation that is fast-paced, and physically overwhelming. Often that feeling is heighted by a sense of mass confusion, and personal ineptness. Term was first coined to describe the "D-Day" invasion of World War 2. When Allied ships inflitrated Nazi shores, and infantry troops literally had to "hit the ground running", to keep from getting shot.

When someone is hit by a car that proceeds to just drive off. Running is not involved.

The act of seducing a girl in order to smash her, and then shortly after, fleeing from the scene, leaving the girl wondering what the fuck just happened. In a hit and run, you either don't give the girl your name and number, or you give her a false name and number. It is a common scenario in one night stands, and is usually demeaning and humiliating for the woman, but gives the male something to gloat about to his friends.

After toking up, the act of leaving the gathering without socializing or at the very least saying thanks.
Taking a hit and leaving. Very uncool behavior.

When one silently farts near a person or group, then slowly walks away inconspicuosly. Usually a sign of disrespect to the receiving party.

The act of downloading a file through bittorrent and immediately stopping any seeding as soon as the file has finished downloading. This is done to save bandwidth and avoid lawsuits.

a meaningless one night stand