as mentioned above, Mencken includes the possible racehorse connection in a footnote in The American Language, but what the AHD didn't mention is that Mencken goes on: A variant etymology was printed in the London Morning Post, Jan. 31, 1935. It was so precious that it deserves to be embalmed: "Among the Negores in Harlem it is the custom for each household to keep a goat to act as general scavenger. Occasionally one man will steal another's goat, and the household debris then accumulates, to the general annoyance."