Green’s Dictionary of Slang

1. the extreme effects of a drug, usu. strong cannabis.

2000		N. Griffiths Grits 373: It’s just like, yer know, total headfuck. Paralysis like. Yew carn move out-a yer fuckin chair, mun.
2018		I. Welsh Dead Man’s Trousers 28: He faux wanks the cock [...] I luff house muzik! It is the ultimate headfuck!

2. something that causes problems, a worry.

1983		R. Price Breaks 236: Every second that passed in conversation was just increasing the headfuck.
1991		B. Hamper Rivethead (1992) 16: They accepted their birthrights and strode sheep-like into the vast head-fuck of the factories.
2000		J.J. Connolly Layer Cake 18: Avoid night-clubs, bars, restaurants and mini-cab firms because they’re a total headfuck.
2007		Wildhearts ‘My Baby Is a Headfuck’ 🎵 ’Cos she’s the kind of girl who’ll take your heart / And leave you feeling worse than you did at the start / ’Cos she’s a headfuck, my baby is a headfuck .
2011		J.J. Connolly Viva La Madness 277: It meant a lifetime of headfuck, knowing he’d been had over by Jesus.
2017		G. Gilmore Headland [ebook] He frowned the idea away — too big a head-fuck.
2020		G. Armstrong Young Team 126: The logistical heed-fuck [...] makes fur grim watchin.