Wild and vigorous sex done with the intention of putting the other person through the wall. The wall may be literal or metaphorical. The point is to fuck the person hard, deep, and with quick, almost violent strokes. Despite the nature, the slamfuck is usually done with good intentions.
What a freak! Don't go in for that nice and gentle shit. She likes a good, hard slamfucking.
by D.S.Machina October 24, 2006
To ravage the pussy or ass like no other. You succeeded in slam fucking if the reciever is screaming and crying in agony.
Brad - "Man, I'd SLAM FUCK Paris Hilton!"
by AMS May 07, 2005