Green’s Dictionary of Slang

alcohol, esp. beer.

1859		Hotten Dict. of Modern Sl. etc. 96: bivvy, or gatter beer; ‘shant of bivvy,’ a pot, or quart of beer.
1861		Melbourne Punch ‘The Lay of the Lags’ 14 Mar. 1/1: Chuffers, pass the shant of bivvy.
1873		Sl. Dict.
1881		Newcastle Courant 2 Dec. 6/6: Here’s a boozing ken, we’ll have a shant or two of bivvy.
1909		J. Ware Passing Eng. of the Victorian Era.