When you throw your fist in the air in an excited/victorious manner, often accompanied by a lunge of the body.

(noun): the type of douchesbag seen in public- particularly nightclubs and beaches- reminiscent of "The Jersey Shore". Characterized by medically disturbing tans, overly-producted hair, and under-sized Affliction T-shirts. Often observed performing a simplistic, repetitive motion, also referred to as a "fistpump ".