M. T. i.e. empty: as, Take away this bottle, it has Moll Thompson’s mark upon it.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Moll Peatly’s Gig * MollyNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes