Hagarenes or Hagarites
(named after Hagar), a people dwelling to the east of Palestine with whom the tribes of Reuben made war in the time of Saul (1 Chronicles 5:10, 18-20). The same people, as confederate against Israel, are mentioned in Psalms 83:6. It is generally believed that they were named after Hagar and that the important town and district of Hejer on the borders of the Persian Gulf, represent them
Smith's Bible Names Dictionary (1866).