Boyd’s Bible Dictionary:
Either Philistines or Copts of Egypt (Gen. 10:14; Deut. 2:23; Jer. 47:4; Amos 9:7).
Concise Bible Dictionary:
The people of Caphtor (Gen. 10:14; Deut. 2:23; 1 Chron. 1:12).
Jackson’s Dictionary of Scripture Proper Names:
masculine plural of Caphtor