Green’s Dictionary of Slang

a revivifying glass of alcohol.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc.
1920		G. Saintsbury Notes on a Cellar-Book 13: In that blameless Hyperborean district, [...] the worship of the wine of the country did not exclude that of other cheerers. I never drank better claret or champagne than I had given to me 'up there'.