To excite, stimulate, or provoke; or as it is vulgarly called, to egg a man on. Fall back, fall edge; i.e. let what will happen. Some derive to egg on, from the Latin word, age, age.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Eat * Eight EyesNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes