dupe: [17] English borrowed dupe from French, where it was probably originally a humorous application of a dialect word for a ‘hoopoe’, an extravagantly crested bird whose flamboyant appearance seems to have made it the butt of jokes. It presumably represents ultimately an alteration of Old French huppe ‘hoopoe’, sometimes explained as being a conflation of de huppe ‘of the hoopoe’. (English hoopoe [17] is an alteration of an earlier hoop, which came from Old French huppe; its ultimate source was Latin upupa, which originated as an imitation of the bird’s cry.) => hoopoe
