Amalek

dweller in a valley, the son of Eliphaz and grandson of Esau (Gen. 36:12; 1 Chr. 1:36); the chief of an Idumean tribe (Gen. 36:16). His mother was a Horite, a tribe whose territory the descendants of Esau had seized.

Source: Easton’s Bible Dictionary (M.G. Easton, 1897, public domain).