To grin in a glass case; to be anatomized for murder: the skeletons of many criminals are preserved in glass cases, at Surgeons’ hall.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Grimalkin * GrinagogNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes