Charles Ellicott Commentary Genesis 36:15

"These are the chiefs of the sons of Esau: the sons of Eliphaz the first-born of Esau: chief Teman, chief Omar, chief Zepho, chief Kenaz," — Genesis 36:15 (ASV)

Dukes.—Duke is the Latin word dux, a leader; but the Hebrew word alluph signifies a tribal prince. It is derived from eleph, a thousand, used in much the same way as the word hundred with us for a division of the country.

Probably it was one large enough to have in it a thousand grown men, whereas a hundred in Saxon times was a district in which there were a hundred homesteads. For this use of it, see Micah 5:2. Each alluph, therefore, would be the prince of one of these districts, assigned to him as the possession of himself and his seed.