Somebody explained these terms by saying, the first was a man who had a doxy of his own, the second a person who made use of the doxy of another man.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Organ * OschivesNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes