Seir

rough; hairy.

(1.) A Horite; one of the "dukes" of Edom (Gen 36:20-30).

(2.) The name of a mountainous region occupied by the Edomites, extending along the eastern side of the Arabah from the south-eastern extremity of the Dead Sea to near the Akabah, or the eastern branch of the Red Sea. It was originally occupied by the Horites (Gen 14:6), who were afterwards driven out by the Edomites (Gen 32:3; 33:14; 33:16). It was allotted to the descendants of Esau (Deut 2:4; 2:22; Josh 24:4; 2Chr 20:10; Isa 21:11; Ezek 25:8).

(3.) A mountain range [not the Edomite range, (Gen 32:3)] lying between the Wady Aly and the Wady Ghurab (Josh 15:10).

EBD - Easton's Bible Dictionary