Green’s Dictionary of Slang

1. a psychotic, a randomly, obsessively violent person, someone who cannot control their temper.

1973		(con. mid-1960s) J. Patrick Glasgow Gang Observed 233: Heid-banger – someone who allegedly hits his head against walls, and so thought to be mad.
1981		T. Wilkinson Down and Out 63: They’re fucking head-bangers, those Scottish bastards.
1993		T. Winton Lockie Leonard: Scumbuster (1995) 129: There was a mob of head-bangers and bogans crowded around the music and motorbike shelves.
2000		J.J. Connolly Layer Cake 33: From then on in he became a right fuckin head-banger, a complete fuckin head-the-ball.
2004		(con. 1960s-70s) T. Taylor Top Fellas 120/1: These kids [...] weren’t sharpies, they were just head bangers.
2011		J.J. Connolly Viva La Madness 283: You can’t argue with headbangers.
2023		A. Rawnsley in Oberserver 23 Nov. 🌐 The head-bangers [...] are clamouring for the government to ignore the highest court in the land and ‘just put the planes in the air’.

2. (US black) something crazy and/or astonishing.

1988

G. Tate ‘Public Enemy’ in Flyboy in the Buttermilk (1992) 127: ‘She Watch Channel Zero?!’ a headbanger about how brainless the bitch is for watching the soaps.

3. (also banger) in weak or affectionate use of sense 1.

2001		I. Welsh Glue 96: — Eh ye cannae git VD offay lassie’s tit? By feelin it likesay. Ah starts laughin, n Billy does n aw. — You’re a heidbanger, Ewart.
2020		G. Armstrong Young Team 89: Some banger shouts suhin daft n makes yi laugh.
2020		G. Armstrong Young Team 135: [T]here fuckin heidbangers wid be hammerin it aw day.