A loose stone in a pavement, under which water lodges, and on being trod upon, squirts it up, to the great damage of white stockings; also a sharper neatly dressed, lying in wait for raw country squires, or ignorant fops.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Beau-nasty * BecalmedNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes