Nephew n. : A grandson or grandchild, or remoter lineal descendant.

Nephew n. : A cousin.

Nephew n. : The son of a brother or a sister, or of a brother-in-law or sister-in-law.

Example:
Can I file my Nephew as a dependent on my taxes?

Taxonomy
Nephew, nieces, sibling, daughter, sister, free encyclopedia, band, Search, brother/sister, spouse, half-brother, half-sister, sister-in-law, brother-in-law, stepbrother, King Arthur, Tolkien, Kings of Rohan.

Defination from the web:
Nephew is a term referring to the son of one's sibling or spouse's sibling, and niece to the daughter of one's sibling or spouse's sibling. ... 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 ...