canard

In 16th-century France, vendre des canards à moitié was a colorful way of saying "to fool" or "to cheat." The French phrase means, literally, "to half-sell ducks." No one now knows just what was meant by "to half-sell"; the proverb was probably based on some story widely known at the time, but the details have not survived. At any rate, the expression led to the use of canard, the French word for "duck," with the meaning of "a hoax" or "a fabrication." English speakers adopted this canard in the mid-1800s. The aeronautical sense of canard, used from the early days of flying, comes from the stubby duck-like appearance of the aircraft.