Today is the fifth of November. It is a day when British folk "Remember, remember...Gunpowder treason and plot." In 1605, in complicity with Robert Catesby and three others, says the BBC, Guy Fawkes hatched a devious plan to blow the British parliament sky high and assassinate King James I. Though Fawkes ultimately failed, the plot - and its associated legend - lives on.
Notwithstanding the yearly celebration (an anti-Catholic holiday that evokes Fawkes' fiasco through fireworks, burning barrels, and effigies of Fawkes and the Pope set aflame) Guy Fawkes' legacy has carried on in at least one other important way. (And I don't mean "V for Vendetta" or Anonymous' co-opting of the famous, Fawkes masks.) The very word "guy" and the plural, somewhat gender-neutral word "guys" stems from Fawkes himself, according to pieces both at the Washington Post and Smithsonian.
From the Post article itself: "The word has surprisingly black roots: It's derived, etymologists believe, from the name Guy Fawkes, one of the leaders of the Gunpowder Plot that attempted to assassinate King James I in 1605. Years after Fawkes's plan was foiled, British children paraded his effigy around on Nov. 5 - a custom that, over the course of decades, made "guy" a sort of slang, first for a poorly dressed person, and then more generally for a man ( ... of any wardrobe). The word 'guy,' as used today to indicate a 'man, fellow, person, individual, creature,' didn't exist in 1605. In fact, even the name Guy, a name with Norman French origins given to poor Guy Fawkes by his parents in 1570, was relatively rare in England at the time."
Where "guy" originally had strong negative connotations it eventually became the more neutral, everyday term that is often used in conversations today.
