from
Easton's 1897 Bible Dictionary
Pelethites
mentioned always along with the Cherethites, and only in the
time of David. The word probably means "runners" or "couriers,"
and may denote that while forming part of David's bodyguard,
they were also sometimes employed as couriers (2 Sam. 8:18;
20:7, 23;1 Kings 1:38, 44; 1 Chr. 18:17). Some, however, think
that these are the names simply of two Philistine tribes from
which David selected his body-guard. They are mentioned along
with the Gittites (2 Sam. 15:18), another body of foreign troops
whom David gathered round him.