Going to the bar and getting a quick drink before going home or getting back to work. 1 and dones are followed by a 2 and through, 3 and flee, or a 4 and door, etc.. Anything after 4 and door is a full on party and you were just kidding yourself about "getting a quick drink".
1. Yo where you going for lunch? You down for a 1 n done?
2. Damn these folks at work stressin me out.. I may need a 1 n done before I go home.