A nose. Snitchel his gigg; fillip his nose. Grunter’s gigg; a hog’s snout. Gigg is also a high one-horse chaise, and a woman’s privities. To gigg a Smithfield hank; to hamstring an over-drove ox, vulgarly called a mad bullock.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Gift of the Gab * GiggerNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes