Thin, ill-shaped legs: a corruption of the French word jambes. Fancy gambs; sore or swelled legs.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Gallows Bird * GambadoesNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes