One whose employment is to empty necessary houses; called also a tom-turd-man, and night-man: the latter, from that business being always performed in the night.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Gold Droppers * GoldfinchNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes