What did thought do? lay’in bed and beshat himself, and thought he was up; reproof to any one who excuses himself for any breach of positive orders, by pleading that he thought to the contrary.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Thorough Stitch * Three To OneNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes