guy

Where it comes from

A guy is ordinarily a man or person. The noun began much more specifically with Guy Fawkes, one of the Gunpowder Plot conspirators. Bonfire Night celebrations burned effigies of Fawkes, and those figures were called guys. The name then escaped the bonfire: in Britain, guy could mean a grotesquely or poorly dressed person. In nineteenth-century American English, the insult weakened until a guy was simply a man or fellow. Later, plural you guys broadened further in many speakers’ usage. The route runs from one named man to his effigy, from the effigy to an insult, and from the insult to an everyday person.

How the meaning developed

An executed conspirator’s first name passed through an effigy and an insult before becoming an everyday word for a person.