Like an owl in an ivy bush; a simile for a meagre or weasel-faced man, with a large wig, or very bushy hair.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
just-ass * kateNathan Bailey's 1721 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes