Brown Driver Briggs

 Jobab = "a desert"
1. the last in order of the sons of Joktan, a descendant of Shem
2. one of the kings of Edom
3. the king of Madon, located in northern Canaan, and one of the kings
who opposed Joshua during the conquest and who were routed at Meron
4. head of a Benjamite house
5. another Benjamite