Nephew and niece

A nephew is the son of someone's brother or sister. A niece is the daughter of the person's brother or sister. To the nephew or niece, the person is their uncle or aunt. The relationship of aunt/uncle to niece/nephew is an example of second-degree relatives, meaning that their coefficient of relationship is 25%. In some cultures and families, it is common to call the child of one's cousin a "niece" or "nephew". In old English, the son of one's sister was called a sister-son.

Detail

A sororal or fraternal relative is one who is related through their sister or brother. For example a sororal niece is the subject's sister's child. An in-law is a relationship that is not by blood, but instead by marriage. The in-law shares the in-law relationships of the spouses relatives. For niece or nephew in-law could be the child of a spouse.

Women

• niece: sibling's daughter.
• half-niece: half-sibling's daughter
• sororal niece: sister's daughter.
• fraternal niece: brother's daughter.
• double-half-niece: a person who is a daughter of both of the subjects half-siblings.
• grandniece (or great-niece): sibling's granddaughter.
• great-grandniece (or great-great-niece): sibling's great-granddaughter.
• niece-in-law: spouse's niece.
• niece-in-law: nephew/niece's wife.
• co-niece-in-law: spouse's nephew/niece's wife.
• stepniece: stepsibling's daughter.
• stepniece: sibling's stepdaughter.

Men

• nephew: sibling's son.
• half-nephew: half-sibling's son.
• sororal nephew: sister's son.
• fraternal nephew: brother's son.
• double-half-nephew: a person who is a son of both of the subjects half-siblings.
• grandnephew (or great-nephew): sibling's grandson.
• great-grandnephew (or great-great-nephew): sibling's great-grandson.
• nephew-in-law: spouse's nephew.
• nephew-in-law: nephew/niece's husband.
• co-nephew-in-law: spouse's nephew/niece's husband.
• stepnephew: stepsibling's son.
• stepnephew: sibling's stepson.

References

•   "Nephew". Encyclopædia Britannica (Eleventh) 19. (1911). Cambridge University Press.