'Gilpin'

There's some great period slang used in this movie, such as when Eddie refers to Danny's cap as a "dicer" and a "skimmer". The one word that gets used over and over is "gilpin", which was clearly meant to refer to someone as a fool or a mug. Doing a Google search for the word's definition is fruitless, however. It's only recognized as a surname. Has anyone else come across this word in another movie or in literature? Was it used only in the 20's? And did it's meaning come from an actual person named Gilpin who had done something foolish?