Brown Driver Briggs

 Hadad = "mighty"
1. son of Ishmael
2. a king of Edom who gained an important victory over the Midianites
on the field of Moab
3. another king of Edom, with Pau for his capital
4. a member of the royal house of Edom who escaped the massacre under
Joab and fled with a band of followers into Egypt; after David's
death, he returned to his own country