Word Origin & History
of unknown origin; the "Dictionary of American Slang" gives a first reference of 1874 (but without citation), which, if correct, would rule out the usual theory that it is from the proper name of T.W. Earp, a student at Oxford c.1911, who kindled wrath "in the hearts of the rugger-playing stalwarts at
Oxford, when he was president of the Union, by being the last, most charming, and wittiest of the 'decadents.' "