Thirteen pence halfpenny; which, according to the vulgar tradition, was thus allotted: one shilling for the executioner, and three halfpence for the rope, —N. B. This refers to former times; the hangmen of the present day having, like other artificers, raised their prices. The true state of this matter is, that a Scottish mark was the fee allowed for an execution, and the value of that piece was settled by a proclamation of James I. at thirteen pence halfpenny.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Hanger On * HankNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes