Italian: apparently of Germanic origin, representing a feminine short form of names containing the element gild ‘sacrifice’ (compare e.g. Hermengildo). Its occasional use in the English-speaking world since the 19th century may have been prompted by the character in Verdi's Rigoletto, the innocent daughter of the hunchback jester Rigoletto, who becomes the object of the Duke of Mantua's affections and is murdered on her father's orders as the result of a series of misunderstandings.
English (of Norman origin): 1. nickname for an old man, or for the elder of two bearers of the same personal name, from Anglo-Norman French viel ‘old’ (Old French vieil). 2. metonymic occupational name for a calf-herd or nickname for a docile, calf-like person, from Anglo-Norman French ve(e)l ‘calf’ (Old French veel).