One 's sibling - in - law is one 's spouse 's sibling, or one 's sibling 's spouse, or ones 's spouse 's sibling 's spouse. By gender, this is specified as brother - in - law for one 's spouse 's brother, one 's sibling 's husband, or one 's spouse 's sibling 's husband, and sister - in - law for the one 's spouse 's sister, one 's sibling 's wife, or one 's spouse 's sibling 's wife.
how do you call your brother in law wife
sister - in - law