c.1300, bordel "house of prostitution," from Old French bordel "small hut, cabin; brothel" (12c.), diminutive of borde "hut made of planks," from Frankish *bord "wooden board" or some other Germanic source related to board, n.1. The modern form is a result of the French word being borrowed by Italian then passed back to French with a suffix and re-borrowed into English in its current form by 1590s.