Smith's Bible Dictionary (1863)
(executioners) and of King David. , (2 Kings 11:4) and as couriers, (1 Kings 14:27) But it has been conjectured that they may have been foreign mercenaries, and therefore probably Philistines, of which name Pelethites may be only another form.
Hastings' Dictionary of the Bible (1898)
CHER'ETHITES and PEL'ETHITES (executioners and couriers) formed the body-guard of King David. 2 Sam 8:18; 2 Sam 5:18; 2 Sam 20:7. It is probable they were mercenaries, originally Philistines, for Cherethite is connected with Pelethite, which was, it is likely, only another form of the word Philistine.