The French had an old saying (going back to Middle French), "vendre des canards a moitie," literally, "to half-sell ducks." It meant "to fool" or "to cheat." That expression led to the use of "canard," the French word for "duck," to mean "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. "Canard" can even mean simply "duck" in English as well, but this use is limited to the specialized realm of cooking. The French word itself is ultimately derived from "caner," Old French for "cackle," a word of imitative origin.
In 1845, the editors of the _Edinburgh Review_ felt compelled to use the German "schwarmerei" to describe fanatical enthusiasm because the concept seemed so foreign to them. In commenting on the writings of German critic and dramatist Gotthold Lessing, they declared "schwarmerei" to be "untranslatable, because the thing itself is un-English." That German word derives from the verb "schwarmen," which means not only "to be enthusiastic or fanatical" but also "to swarm" (it was used to refer to bees), and its ancestors were part of Old High German. Ironically, the _Edinburgh Review's_ use (the first ever documented in an English publication) seems to have contributed to making the word much more English, and it has since become a naturalized citizen of our language.
In 1920, a 38-year-old Italian immigrant named Charles Ponzi offered a huge return on investments in postal coupons. He quickly amassed $9,500,000 sent to him by people anxious to make a quick buck, but very few of his investors made even a dime because his company was fictitious and the whole deal turned out to be a scam. Ponzi's name stayed in the headlines during his trial and even after his larceny conviction, but it wasn't immediately adopted as a general term for a shady investment deal. The earliest citations for the generic use of "Ponzi scheme" didn't appear in print until 1973. By the way, when Ponzi died (several convictions and a deportation later) in 1949, his estate totalled $75.00 -- just enough to pay funeral expenses.