To catch the; a trick practised upon ignorant country boobies, who are decoyed into a barn under pretence of catching an owl, where, after divers preliminaries, the joke ends in their having a pail of water poured upon their heads.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Outs * Owl In An Ivy BushNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes