Young, inexperienced, unacquainted, ignorant. How green the cull was not to stag how the old file planted the books. How ignorant the booby was not to perceive how the old sharper placed the cards in such a manner as to insure the game.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Green * Green BagNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes