Green’s Dictionary of Slang

rushlight n.

[SE rushlight which ‘blazes up’]

a fiery drink.

[UK]W. Toldervy Hist. of the Two Orphans III 112: Taking a dirty paper out of her bosom, in which was written the following words: Tape, glim, rushlight, white port, rasher of bacon, gunpowder, slug, wild-fire, knock-me-down, and strip-me-naked.