Green’s Dictionary of Slang

bouse n.

also bouze, bowse
[Du. buizen or Ger. bausen, to drink to excess. The OED’s first use is c.1300, but this may be only the drinking vessel, not its contents; the Du. term too is rooted in buise, a large drinking vessel. Although bouse can be found in ME, its popularity came with its Und. usage ]

1. [mid-16C+] (UK Und.) drink; thus ben bouse, good drink; for later uses see also booze n.

2. [late 17C] a toast.