Today's false etymology is brought to you by the letter Ξ and the restaurant business: "Eighty-six".
The term "eighty-six", as everyone knows, means to be out of something, as in, "We're eighty-sixed on bread. And spoons. And alcoholic beverages. We have iced tea and tortillas." It can also mean to get rid of something or someone, as, "Eighty-six that guy in the hat, and I don't care how many teeth he loses."
I have heard a number of attempts to trace the origin of this term, none truly convincing. But tonight I realized that it is of course from the Greek εξωθεω, I thrust out, I expel. Probably from the future tense: εξωθησω
Ta da! A false etymology just for you. I can't believe I do this sort of thing for free.