swack is a type of hit. it is achieved my placing one's hand in
the position used to smack oneself in the chest in the "retard" style. instead of hitting your own chest though, you swing your arm out and hit other people as if the hand was a crude whip, then quickly draw your hand back.
This
definition was made in 2001, when tw o
floridian boys were bored and began hitting each other in the swack style. They soon named the hitting form, swacking.