Who invented the word guy?

Answer 1

Guy as a self-descriptive word had two stages and roots underbroken by the Gunpowder Plot of 1605.

Early it was a doublet of guide; the first reflex was written in 1325: http://oed.com/view/Entry/82781 Song of Yesterday 35 in Early Eng. Poems & Lives Saints (1862) 134 A syker ground who wol him gy I rede he þenke on ȝusterday. gi, gu, and gy were Norman and Romance dialects for w; gy was the reflex of wite by Old Low Franconian. The first guie was attested in La Chanson de Roland about 1050: fort espi li guie.

After the Plot guy was instead called for ropes, chains, or wires: 1620 J. Taylor Praise of Hemp-seed 10 Shrowds, ratlings, lanyards, tackles, lifts, and guies. This novelty could spring from the rope that Guy Fawkes was hanged with. Then it was reinvented by thugs in Guildford, England in 1820 who named themselves after Guy Fawkes and went by homes in masks, broke and burnt property, and struck anyone in their way with spiked clubs. The Guy namesake is first attested in 799 for Guy of Nantes of Guideschi (Austrasian), later Guidoni (Spanish), Vitone (Italian), or Widonides (Francish). His grandchildren became Guy I, Guy II, and Guy III. Guy was the Old Francish reflex of Widu, wood.