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.
A very large penis. Not only long, but has a girth that cannot be ignored. Known for preventing many woman from ever walking again and causing severe bruising. You might as well literally try to have sex with a hammer.
Girl 1: "Hey did you see Terrell at practice? You could totally see his junk when he was wearing that spandex!"
Girl 2: "I feel sorry for his girlfriend. The Hammer he is packing would kill me. "
It all starts when a girl is sucking on your balls. You tell her to go lower, lower, lower, until she gets to your chocolate starfish. Then you flex your abs as hard as you can and blow ass in her face. If you accidentally shart you have successfully performed the infamous dirty hammer.