Seir - (Easton's Bible Dictionary)
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, 16). It was allotted to the descendants of Esau (Deut. 2:4, 22; Josh. 24:4; 2 Chr. 20:10; Isa. 21:11; Exek. 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).