To lay, place, or hide. Plant your wids and stow them; be careful what you say, or let slip. Also to bury, as, he was planted by the parson.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Plant * PlateNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes