When taking the ball out the defender can say, "check" (throw me the ball, and I'll give it back... typically to make sure everyone on defense is ready)... If the offense (guy taking the ball out) says, "three feet, no check" before the defender says, "check", the defender don't get to check the ball and he/she needs to back up at least three feet.
This term is used a lot when playing street basketball to imply that you shouldn't get to close to the person you are trying to block. Me and my friends say it when someone you're talking to gets to close to you or is invading your personal space.
A girl is at a bar and a guy walks over to her to make a conversation by getting really close to her face with his face and his breathe really stinks.
Guy:"Hhhhhey beautiful. Hhhhhhhow are you tonight?"
Girl: "Hey man! Three feet no check!" (As she puts her hand out and pushes him out of her face)
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).