The proper name Guy is derived, via French, from the Old German Wido, either from wit, meaning wide, or from witu, wood.
Wido has become Guy in French because in words of Germanic origin, when initial, the labio-velar approximant /w/ has regularly become the velar /g/. For instance, in the French noun loup-garou, the element garou corresponds to English werewolf—in fact, loup was added when the notion of wolf expressed by garou had been forgotten. Likewise, Galles corresponds to Wales, gaufre corresponds to wafer, and gardien to warden—English guardian is a later borrowing from French. In French, this velar is spelt gu before the vowels e and i, as in guerre, corresponding to war, and Guillaume, to William.
The proper name Guy came to England with the Normans in the 11th century, and subsequently became popular through the medieval romance Guy of Warwick.
Bearers of the name over the years have included the wicked Guy of Gisborne in the Robin Hood legends, the central character in the Walter Scott novel Guy Mannering (1815), and the French writer Guy de Maupassant (1850-93).
Variants in other languages include Italian Guido.
On 4th November 1605 in London, Guy Fawkes* (1570-1606) was arrested for having planted some twenty barrels of gunpowder in the cellars of the Houses of Parliament as his part in a conspiracy by a small group of Catholic extremists to blow up James I and his Parliament on the following day.
The failure of this conspiracy, now known as the Gunpowder Plot, is still commemorated by the traditional searching of the vaults before the opening of each session of Parliament, and by bonfires and fireworks annually on 5th November, which is called Bonfire Night or Guy Fawkes Night. The effigies of Guy Fawkes, made from old tattered clothes stuffed with straw or rags, and burnt in these bonfires, came to be called guys. The word is first recorded in this sense in the following from a letter that William Peregrine Peter Burrell (1788-1852) wrote to the Scottish antiquary and artist Charles Kirkpatrick Sharpe (1781-1851) on 26th September 1806:
I am growing quite frisky, and now, after having lost completely the talents of eating and sleeping, begin to do both in the prettiest manner. Why, man, a month ago there was neither shape nor make in me. I had vaisted avay all to nothing, and my vaiting-voman nearly expired with fright at being daily obliged to take my stays in. No guy ever matched me.
The use of the word was extended to other similar effigies, and then to a person of grotesque appearance or dress. This sense is first recorded in a letter that the English traveller and author Julia Charlotte Maitland (1808-64) wrote on her way to India on 3rd September 1836:
The thermometer now stands at 78° in the day, and higher, I should think, in the night; but our cabin is certainly the coolest of any, and I have not yet found the heat unbearable. The gentlemen are all “rigged Tropical,” with their collars turned down, and small matters of neckcloths;—grisly Guys some of them turn out!
In the United States, by the mid-19th century, guy had been generalised to mean simply a man or a fellow, and its pejorative connotations were lost. The American author George Ade (1866-1944), in particular, used the word in Artie: A Story of the Streets and Town (1896); for example:
“I got friendly with a guy that was standin’ around.”
“I wish I knew where I could get some brainy guy to gi’ me lessons on this game [= the game of pool].”
By extension, used in the plural, the word now refers to the members of a group regardless of sex.
* Recorded in a number of spellings, Fawkes is, via Norman Faulques, Fauques, derived from a Germanic nickname meaning literally falcon.