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 country from which, beside the Caphtorim, came some of the Philistines. They sprang from Mizraim, son of Ham (Deut. 23; Amos 9:7). In Jeremiah 47:4 (margin) the “isles” may only signify “maritime border.” Caphtor is supposed to be somewhere in Egypt, but has not been identified. See CASLUHIM
Strong’s Dictionary of Hebrew Words:
Meaning:
or (Am. 9:7) Kaphtowr {kaf-tore'}; apparently the same as 3730; Caphtor (i.e. a wreath-shaped island), the original seat of the Philistines
Jackson’s Dictionary of Scripture Proper Names:
as if to interpret: knop: he bowed down to spy out
Potts’ Bible Proper Names:
Seeking and inquiring; a wreath or crown; hollow goblet:―primitive seat of the Philistines, Jer. 47:4. {Quaerens}