The new drop; a contrivance for executing felons at Newgate, by means of a platform, which drops from under them: this is also called the last drop. See Leaf. See Morning Drop.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Drommerars * Drop a CogNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes