A runner, or courier, for the rapid transmission of letters, etc. (2 Chronicles 30:6; Esther 3:13,15; 8:10,14; Job 9:25; Jeremiah 51:31). Such messengers were used from very early times. Those employed by the Hebrew kings had a military character (1 Samuel 22:17; 2Kings 10:25, "guard," marg. "runners"). The modern system of postal communication was first established by Louis XI. of France in A.D. 1464.
This word sometimes also is used for lintel or threshold (Isaiah 6:4).
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Post'". "Easton's Bible Dictionary".