Latinate feminine form of Felix. It was popular in Britain in the medieval period (with the vernacular forms Felice, Felis), but by the 16th century it had become confused with Phyllis. In modern times it is in only occasional use.
English: from the medieval personal name Wiot, Wyot, Gyot, which derives from the Old English personal name Wīgheard, composed of the elements wīg ‘war’ + heard ‘hardy’, ‘brave’, ‘strong’. Under Norman influence it was also adopted as a diminutive of both Guy 1 and William.