Green’s Dictionary of Slang

metalhead n.

[SE (heavy) metal + -head sfx (3)]

(orig. US teen) a fan of heavy metal music.

[US]Eble Campus Sl. Oct.
[US]M. Myers et al. Wayne’s World [film script] We pull back to reveal Alan Nilan, a large Viking-like metal head on camera one. And Terry Roberts, a cleaner-cut metal head on camera two.
[Aus]D. McDonald Luck in the Greater West (2008) 6: The devotion of the metal-heads at his school seemed contrived to him.
[SA]IOL News (Western Cape) 10 Feb. [Internet] They will have all the metal heads and goths [...] dusting off their Docs.