A physical action in anime when a character falls over out of sheer exasperation. Usually after another character says something really stupid. Used for comic purposes.
Really funny when done in real life.
Character 1: This guy's a decendant of the famous Dr. Faust who made a pact with the devil. He's dangerous!
Character 2: So... that's why he's wearing a white jacket! Because he's a doctor!
*Character 1 face vaults*