Uneven, having one side larger or heavier than the other: boys’ paper kites are often said to be lop-sided.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Loophole * To LopeNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes