niece: [13] Niece comes ultimately from *neptī-, the feminine form of Indo-European *nepōt- (source of English nephew). This passed into Latin as neptis ‘granddaughter, niece’, which in post-classical times became *neptia. Old French took it over as niece – whence English niece. *Neptī- also had a Germanic descendant, *niptiz, which now survives only in German nichte and Dutch nicht ‘niece’. => nephew[niece etymology, niece origin, 英语词源]