'Brother in law' in the Bible

The children of the Kenite, Moses' brother-in-law, went up out of the city of palm trees with the children of Judah into the wilderness of Judah, which is in the south of Arad; and they went and lived with the people.

Now Heber the Kenite had separated himself from the Kenites, even from the children of Hobab the brother-in-law of Moses, and had pitched his tent as far as the oak in Zaanannim, which is by Kedesh.