A drunken man or woman taken up by the watch, and confined in the, watch-house. CANT. To smell a rat; to suspect some intended trick, or unfair design.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
See also the definition in Nathan Bailey's 1736 dictionary of canting and thieving slang.
Rascal * RatsNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes