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.
John: Dude, I pulled a hit and run on Jessica last night!
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.
-Bob: "Dude, did you see that? The girl in the red sweat pants totally just left without even talking to us!"
-Jeremy: "That my friend, is a prime example of Hit and Run."
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.
Someone sends an instant message "Hi" to you, and you reply, "Hey! How are you?" -- and then... you wait around.. and nothing. Nothing for like forever. Then they go Idle, and leaves you with a big case of WTF?
Classic case of "hit and run".
Also, can be used when you are having a instant messaging conversation, and they leave you hanging unexpectedly...
Last time I talked to her on Facebook Chat, she did a hit and run.