Nephew

A nephew is a son of one's sibling or half-sibling, and a niece is a daughter of one's sibling or half-sibling. Sons and daughters of siblings-in-law are also informally referred to as nephews and nieces respectively, even though there is no blood relation. The word nephew is derived from the French word neveu. The term "nibling", an analogy to sibling, has been proposed as a gender neutral for nephews and nieces.

• Nephew – son of one's brother/sister (and his/her spouse).
• Niece – daughter of one's sister/brother (and her/his spouse).
• Half-nephew – son of one's half-brother/half-sister.
• Half-niece – daughter of one's half-brother/half-sister.
• Nephew-in-law – son of one's sister-in-law/brother-in-law; husband of one's niece.
• Niece-in-law – daughter of one's sister-in-law/brother-in-law; wife of one's nephew.
• Step-nephew – son of one's stepbrother/sister, or stepson of one's brother/sister, or stepson of one's stepbrother/stepsister.
• Step-niece – daughter of one's stepbrother/sister, or stepdaughter of one's brother/sister, or stepdaughter of one's stepbrother/stepsister.
• Half-nephew-in-law – son of one's wife/husband's half-brother/half-sister; husband of one's half-niece
• Half-niece-in-law – daughter of one's wife/husband's half-brother/half-sister; wife of one's half-nephew
• Step-niece-in-law – daughter of one's wife/husband's stepbrother/stepsister; wife of one's step-nephew
• Step-nephew-in-law – son of one's wife/husband's stepbrother/stepsister; husband of one's step-niece
• Great-nephew – son of one's nephew/niece, grandson of one's sister/brother.
• Great-niece – daughter of one's nephew/niece, granddaughter of one's sister/brother.
• Half-great-nephew – son of one's half-nephew/niece.
• Half-great-niece – daughter of one's half-nephew/niece.

In some cultures and family traditions, it is common to refer to one's first cousin once removed (the child of one's cousin), as a niece or nephew. In archaic terminology, a maternal nephew is called a sister-son, emphasizing the importance as a person's nearest male relative should he have no brothers or sons of his own. The term is used to describe some knights who are nephews to King Arthur and is imitated by J. R. R. Tolkien, especially in lists of Kings of Rohan or dwarves where the sister-son is also heir. Sister-daughter is a less common parallel term for niece.