In the lineal kinship system used in the English-speaking world, a niece or nephew is a child of an individual's sibling or sibling-in-law. A niece is female and a nephew is male, and they would call their parents' siblings aunt or uncle. More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.