Green’s Dictionary of Slang

a particularly energetic style of dance that involves physical collision with other dancers; also attrib.

1980		L.A. Times 29 June (Calendar) 4/1: The mindless ferocity of this Slam dancing bothers longtime L.A. punk enthusiasts who view the younger, beach-area punks as outside agitators bent on destroying the local punk community.
1987		W. Wang [movie title] Slam Dance.
1989		C. Hiaasen Skin Tight 120: A local skinhead gang went into a slam-dancing frenzy.
1991		B. Hamper Rivethead (1992) 101: A kamikaze rage that had about as much to do with the true art of pugilism as slam-dancing had with classical ballet.
1999		Observer Mag. 5 Sept. 33: Judging by the ferocious slam-dancing, the 200-strong crowd approves.
1999		(con. 1980s) L. Leblanc Pretty in Pink 51: Enter the slam dance, which then developed into ‘thrashing,’ a seemingly more violent form of slam dance.
2001		(con. 1975–6) E. Little Steel Toes 143: Now it’s called moshing, once it was slam dancing, and that may have evolved from pogoing.
2002		S. O’Neal Shaquille 87: I was the slam-dance champion of England. I should explain. [...] at the end of the concert, there was this slam-dance contest.