nephew
/ˈnɛf.ju/noun
The son of your brother or sister, or of your spouse's brother or sister.
Its female counterpart is 'niece'. A gender-neutral coinage, 'nibling', exists but remains informal.
Related words
nieceThe daughter of your brother or sister, or of your spouse's brother or sister.uncleA brother or brother-in-law of your mother or father.parentSomeone who brings up a child, whether the child is their own by birth, adoption, or fostering.cousinThe son or daughter of your aunt or uncle.siblingA brother or sister; someone who has a parent in common with you.grandfatherThe father of your mother or father.