A countryman. The dropcove maced the Joskin of twenty quid; The ring dropper cheated the countryman of twenty guineas.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Joseph * JowlNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes