guy"fellow," 1847, originally Amer.Eng.; earlier (1836) "grotesquely or poorly dressed person," originally (1806) "effigy of Guy Fawkes," leader of the Gunpowder Plot to blow up British king and Parliament (Nov. 5, 1605), paraded through the streets by children on the anniversary of the conspiracy. The
male proper name is from Fr., related to It. Guido, lit. "leader," of Gmc. origin (see
guide).