Persons entitled to vote for members of parliament in certain boroughs, from having boiled their pots therein. These boroughs are called pot-wabbling boroughs.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Pothooks and Hangeks * PoulainNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes