'Brother in law' in the Bible

When brethren dwell together and one of them die and have no child, the wife of the dead shall not be given out unto a stranger: but her brother-in-law shall go in unto her and take her to wife and marry her.

But and if the man will not take his sister-in-law, then let her go to the gate unto the elders and say, 'My brother-in-law refuseth to stir up unto his brother a name in Israel, he will not marry me.'