Webster Dictionary(4.00 / 2 votes)Rate this definition: 1  Post(adj) hired to do what is wrong; suborned. 2  Post(noun) a piece of timber, metal, or other solid substance, fixed, or to be fixed, firmly in an upright position, especially when intended as a stay or support to something else; a pillar; as, a hitching post; a fence post; the posts of a house.