a daughter of your brother or sister
"I invited my niece to visit for her birthday, and she is actually my brother's daughter."
A daughter of one’s sibling, brother-in-law, or sister-in-law; either the daughter of one's brother ("fraternal niece"), or of one's sister ("sororal niece").
"My niece loves to visit her aunt every summer."
A surname.
"Please remember that Niece is actually a family name in our community, not just a title for your sister's daughter."
The word "niece" comes from the Old French nece, which originally meant both "niece" and "granddaughter." This term traces back to Latin neptis and ultimately derives from a Proto-Indo-European root meaning "granddaughter or niece."