When a chick doesn't know how to give a handjob and places one hand around the penis and continuously pounds the head of the penis with the palm of her other hand, acting as a hammer.
Kristin gave me The Hammer last night. My dick is gonna be bruised for a week now.
The Hammer is the act of taking a closed fist and beating off your dick into submission while applying as much force as humanly possible resulting in a small, bruised, and compressed cock.
Dude 1: "Bro I got so mad at my mom last night and had to release my anger by using The Hammer, its my favorite tool of choice."
Nickname for pro bowler Fred Williamson and given because of the blow to the head style, clothesline, forearm chop that he brutalized other players with. A blow that was perpendicular to the surface of the Earth. In other words he would swing his arm like a Hammer, at his opponent thus braking their helmet. This move is no longer legal in pro football. Inducted into the Indiana Football Hall of Fame in 1996.