An artificial sore made with unslaked lime, soap, and the rust of old iron, on the back of a beggar’s hand, as if hurt by the bite or kick of a horse.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Foot Wabbler * Footy DespicableNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes