Meaning

noun the position where someone (as a guard or sentry) stands or is assigned to stand

noun military installation at which a body of troops is stationed

noun a job in an organization

originEtymology tree Latin postisbor. Old English post Latin postisder. Old French postbor. Middle English post English post Inherited from Middle English post, from Old English post (“pillar, door-post”) and Old French post (“post, upright beam”), both from Latin postis (“door, post, doorpost”).

Etymology from Wiktionary, CC BY-SA 3.0