Hastings' Dictionary of the Bible 
HORITES . The pre-Edomitic inhabitants of Seir or Edom according to Genesis 14:6 (a late passage) and Deuteronomy 2:12; Deuteronomy 2:22 (D [Note: Deuteronomist.] 2). Apparently they commingled with the Edomite invaders, for Genesis 36:20-21; Genesis 36:29 (P [Note: Priestly Narrative.] 3) counts them among the descendants of Esau. The name is usually taken to mean ‘cave-dwellers,’ and this is probably correct. There are many tombs in the rocks at Petra (cf. Robinson, BRP [Note: RP Biblical Researches in Palestine.] 2 ii. 129, 134), and some of these, like some at Beit Jibrin and some recently discovered at Gezer (cf. PEFSt [Note: Quarterly Statement of the same.] , 1902, pp. 345 ff., and 1903, pp. 9 12) may have been used as dwellings originally. Sayce ( HCM [Note: CM Higher Criticism and the Monuments.] 203 ff.) derives the name from a root meaning ‘white’ as contrasted with the ‘red’-skinned Edomites, while Hommei ( AHT [Note: HT Ancient Hebrew Tradition.] 261 ff.) takes it as a form of Garu (or Kharu ) of one of the Amarna tablets. Kharu was, however, in Egyptian a name for all the inhabitants of Syria (cf. W. M. MÃ¼ller, Asien und Europa , 148 ff.), and can hardly be connected with Horites . Driver ( Deut . p. 38) favours the explanation as equivalent to ‘cave-dwellers’ or ‘troglodytes.’
George A. Barton.
Holman Bible Dictionary 
The Hebrew word for Horites corresponds to the extrabiblical Hurrians, a non-Semitic people who migrated into the Fertile Crescent about 2000 B.C. The Hurrians created the Mitannian Empire in Mesopotamia about 1500 B.C. and later became an important element in the Canaanite population of Palestine. In locations where there is extrabiblical evidence for Hurrians, the Hebrew term Hivites appears ( Genesis 34:2; Joshua 9:7; Joshua 11:3 ,Joshua 11:3, 11:19 ) as a designation for certain elements of the Canaanite population. The Septuagint (the ancient Greek translation of the Old Testament), however, substitutes Horites for Hivites in Genesis 34:2 and Joshua 9:7 . Also, Zibeon, son of Seir the Horite ( Genesis 36:20 ), is identified as a Hivite in Genesis 36:2 . For these reasons, many scholars equate both Horites and Hivites (the names are quite similar in Hebrew) with the extrabiblical Hurrians.
Nevertheless, the Hebrew text only mentions Horites in Mt. Seir where there is no record of Hurrians. Therefore, another suggestion holds that the biblical Horites were not Hurrians, but simply the original cave-dwelling (the Hebrew hor means “cave”) population of Edom (Mt. Seir). The Hivites, according to this theory, should be identified with the extrabiblical Hurrians.
Daniel C. Browning, Jr.
Bridgeway Bible Dictionary 
The Horites were the original inhabitants of the region around Mt Seir, south of the Dead Sea. When Esau and his descendants moved into the region, they overpowered the Horites and took possession of the land for themselves. It became part of the land of Edom, and the remaining Horites were absorbed into the Edomites ( Genesis 14:6; Genesis 36:20-21; Deuteronomy 2:12; Deuteronomy 2:22; see Edom ).
Hawker's Poor Man's Concordance And Dictionary 
An ancient people, who dwelt in mount Seir. ( Genesis 14:6) Perhaps, in latter days, they were mingled with, and lost their name in the Edomites, or children of Esau. ( Deuteronomy 2:1, etc.)
Easton's Bible Dictionary 
Genesis 14:6 36:20-30 1 Chronicles 1:38,39 Deuteronomy 2:12-22
Kitto's Popular Cyclopedia of Biblial Literature 
Ho´rites or Horim. The people who inhabited Mount Seir before the Edomites [IDUMEA].