guy (n.2) “fellow,” 1847, American English; earlier, in British English (1836) “grotesquely or poorly dressed person,” originally (1806) “effigy of Guy Fawkes,”

Dude. 1883, “fastidious man,” New York City slang of unknown origin; recent research suggests it is a shortening of Yankee Doodle, based on the song’s notion of “foppish, over-fastidious male” (compare macaroni). The vogue word of 1883, originally used in reference to the devotees of the “aesthetic” craze, later applied to city slickers, especially Easterners vacationing in the West (as in dude ranch “ranch which entertains guests and tourists for pay,” attested by 1921).

I’m never using either of these again y’all