A dupe is a furry, ceremonial hat occasionally worn during ancient pagan rituals... or not. Dupe actually means “trick or deceive.” We’re sorry we tried to dupe you into believing the wrong definition.
Dupe can also refer to the victim of a trick or hoax, and — used in this sense — it sometimes conveys the idea that the victim is easily fooled. Dupe comes from the French word for a type of bird called the hoopoe, which has an extravagant crest and a reputation for being dim-witted. (And no, that's not another attempt to dupe you; it's the truth!)