Arsechop

A rough translation of an ancient Taiwanese martial arts move in which the attacker thrusts the edge of his open palm deep into the soft ass crack of his or her opponent. This blow traditionally results in the opponent having a twitchy anus, and making them walk with a mild waddle for five or six steps.

Master Oki did an arsechop on his student. Unfortunately his student's parents were watching at the time, so now he has a lot of explaining to do.