Guinevere

From the Norman French form of the Welsh name Gwenhwyfar meaning "white phantom", ultimately from the old Celtic roots *windos meaning "white" (modern Welsh gwen) and *sēbros meaning "phantom, magical being" [1]. In Arthurian legend she was the beautiful wife of King Arthur. According to the 12th-century chronicler Geoffrey of Monmouth, she was seduced by Mordred before the battle of Camlann, which led to the deaths of both Mordred and Arthur. According to the 12th-century French poet Chrétien de Troyes, she engaged in an adulterous affair with Sir Lancelot.

The Cornish form of this name, Jennifer, has become popular in the English-speaking world.