NIECE Meaning of NIECE in English ■ noun a daughter of one's brother or sister, or of one's brother-in-law or sister-in-law.OriginME: from OFr., based on L. neptis 'granddaughter', feminine of nepos (see nephew ). Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004