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. While it was associated with super-heavyweight wrestlers, the move was innovated by Lou Thesz.
The wrestler first places their opponent face-up across their shoulders, as in an Argentine backbreaker rack, hooks the head with one hand and a leg with the other, and the wrestler will then spin the opponent's head away from them, dropping the opponent down to the mat. Often the wrestler drops to a seated position while spinning the opponent. It was popularized by A.J. Styles with the name "Rack Bomb".
Also known as a sitout two-handed chokeslam and a choke driver. The most common move referred to as a chokebomb sees an attacking wrestler grasps an opponent's neck with both hands and then lift them up into the air. From here the attacking wrestler would throw the opponent back down to the mat while falling to a seated position. This would see the opponent land in a position where their legs are wrapped around the wrestler with their back and shoulders on the mat. This allows the attacking wrestler to lean forward and place both his/her arms on the opponent for a pinfall attempt. A falling version exists, and usually ends with the attacking wrestler pinning the opponent immediately while still holding the throat after the move has already been executed.