A pointless manouvre performed by a drunken idiot in which he pulls his pants and shorts down to his knees, pushes his package down between his thighs which he clamps together to hold said parts firmly in place, then pulls his shirt bottom up over his face and head. Then, while holding everything in place, he scoots away, shrieking for attention at the top of his lungs. Nobody knows why.... but it IS funny to watch.
"On a bet, Larry tried to perform the difficult and legendary Screaming Nun as he left the bar, but unfortunately he ran into a telephone pole and knocked himself unconsious. So naturally his buddies rifled his wallet, took his money and left him lying on the sidewalk."