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).
International Standard Bible Encyclopedia (ISBE)
<p>se'-ir:</p><p>(1) (har se'-ir, "Mt. Seir" (Ge 14:6, etc.), 'erets se`-ir (Ge 32:3, etc.); to oros Seeir, ge Seeir): In Ge 32:3 "the land of Seir" is equated with "the field of Edom." The Mount and the Land of Seir are alternative appellations of the mountainous tract which runs along the eastern side of the Arabah, occupied by the descendants of Esau, who succeeded the ancient Horites (Ge 14:6; 36:20), "cave-dwellers," in possession. For a description of the land see EDOM.</p><p>(2) (har se`ir; Codex Vaticanus Assar; Codex Alexandrinus Seeir): A landmark on the boundary of Judah (Jos 15:10), not far from Kiriath-jearim and Chesalon. The name means "shaggy," and probably here denoted a wooded height. It may be that part of the range which runs Northeast from Saris by Karyat el-`Anab and Biddu to the plateau of el-Jib. Traces of an ancient forest are still to be seen here.</p><p>W. Ewing</p>