Harlot is a borrowing from Old French into Middle English. It did not originally mean a woman of low morals, but rather a vagabond, villain, or otherwise low-life man. From Ancren Riwle, a Middle English tract written sometime before 1225:
And beggen ase on harlot, ȝif hit neod is, his liueneð.
(And beg as does a harlot, give him his needs, his livelihood.)
About a century later, it was being used to refer to a jester or a buffoon, a humorous enterainer. From Richard Rolle of Hampole’s Psalter, written sometime before 1340:
Hoppynge & daunnceynge of tumblers and herlotis, and other spectakils.
(Hopping & dancing of tumblers and harlots, and other spectacles.)
And shortly after that, it came to be used for any man of good cheer, a good fellow. From Chaucer’s Prologue to the Canterbury Tales c.1386 in reference to the sumonour:
He was a gentil harlot and a kynde A bettre felawe sholde men noght fynde.
But the original sense was still in use, as Chaucer shows us in The Reeve’s Tale:
Ye false harlot, quod the Millere, hast?
The word wasn’t applied to women until the 15th century. This is an application of the original sense, meaning a person of low character, not the buffoonish or good fellow sense. From Higden’s Polychronicon of 1432-50:
The harlottes at Rome were callede nonariæ.
16th century translations of the Bible began to use harlot where earlier versions had used whore. This Biblical usage ended up driving the other senses out of the language and harlot came to be associated only with female prostitutes.
The idea that Arlette, the unmarried mother of William the Conqueror is an eponym for harlot is an old one, first suggested circa 1570 by William Lambarde. Arlette was the daughter of Fulbert, a tanner in Falaise, and Robert the Magnificent had his way with her, producing William. It is an interesting and true tale, but it is not the origin of the word.
(Source: Oxford English Dictionary, 2nd Edition)
Copyright 1997-2015, by David Wilton