Green’s Dictionary of Slang

1. to drink; to hold one’s liquor.

1884

Sporting Times 1 Nov. 1/4: He was a stranger at the Drinkeries (late Romano’s) and the waiters did not know how nobly he could glass it.

2. to hit, usu. in the face, with a (broken) glass.

1931		Police Jrnl Oct. 502: The broadsman got chivved and glassed.
1941		Baker Popular Dict. Aus. Sl.
1977		D. Powis Signs of Crime 186: Glassed Jabbed in the face with broken glass.
1993		I. Welsh Trainspotting 80: Boy’s been fuckin glessed! Nae cunt leaves here until ah find oot whae flung that fucken glass!
2003		N. Griffiths Stump 168: Readin about how some fat southern ponce stabbed some cunt or glassed some cunt.
2007		S. Low Boys from Baghdad 86: Asking how I sustained the injury [to my hand], a nurse did give an ‘oh-yeah’ look when I mentioned Iraq and said it looked more like I’d been glassed in a pub.
2008		Camden New Journal (London) 15 May 6/7: Man attacked outside pub [...] Witnesses said the man was glassed outside the George pub in Holmes Road.
2012		(con. 1980s) I. Welsh Skagboys 123: Ah’d love tae gless the taunting pus ay the inscribed McEwan’s Lager Cavalier.
2017		Argus (Brighton) 31 Mar. 🌐 [headline] Man glassed in face while dancing to live music in the street.