Green’s Dictionary of Slang

(drugs) any drug, i.e. heroin, cocaine, categorized as ‘Class A’ under the UK Dangerous Drugs Act (1971); also adj.

1999		Guardian Guide 26 June–2 July 22: A surfeit of booze, broads and Class As.
2005		Guardian Society 13 July 🌐 donal: How would you describe your job? wayne: A and B sales. [...] Class A and class B.
2007		R. Milward Apples (2023) 105: Who cares if the teachers knew I was on Classs As — I was having a Class A time.
2007		N. ‘Razor’ Smith Raiders 247: [of crack] This taste of easy money had Derek hooked [...] on class A product.
2012		(con. 1980s) I. Welsh Skagboys 335: Fuck it, the class war can wait, the class As cannae.
2015		L. McInerney Glorious Heresies 35: ‘[T]here’s a difference between a smoke and the class As, Georgie’.
2020		G. Armstrong Young Team 133: Class A drugs wid dae that tae yi.