Green’s Dictionary of Slang

a drink consisting of the dregs collected from the overflow from the pouring taps, the ends of spirit bottles and similar leavings, which was sold cheaply in gin-shops, particularly to women.

1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.