A powerbomb is a professional wrestling throw in which an opponent is lifted (usually so that they are sitting on the wrestler's shoulders) and then slammed back-first down to the mat. The standard powerbomb sees an opponent first placed in a standing headscissors position (bent forward with their head placed between the attacking wrestler's thighs). He is then lifted on the wrestler's shoulders and slammed down back-first to the mat. A prawn hold is commonly used for a pinning powerbomb.
Powerbombs are sometimes used in mixed martial arts competitions, when a fighter attempts to slam another fighter who has him trapped in a triangle choke. In professional wrestling, it is also sometimes used by a bigger wrestler as a counter to an attempted hurricanrana by a smaller wrestler.