Green’s Dictionary of Slang

loveage n.

[SE lovage, a cordial based on the herb lovage (Ligusticum scoticum)]

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.

[UK]Hotten Dict. of Modern Sl. etc. (2nd edn).
[UK]Hotten Sl. Dict.
[UK]Sl. Dict.