What is Post?

Legal Definition
After. When two or more alienations or descents have taken place between an original intruder ant or defendant in a writ of entry, the writ is said to be in the post, because it states that the tenant had not entry unless after the ouster of the original intruder. 3 Bl. Com. 182. See Entry, limit of.
-- Bouviers Law Dictionary
Legal Definition
A conveyance for letters or dispatches. The word is derived from "positi," the horses carrying the letters or dispatches being kept or placed at fixed stations. The word is also applied to the person who conveys the letters to the houses where he takes up and lays down his charge, and to the stages or distances betwcen house and house. Hence the phrases, post-bay, post-horse, posthouse, etc. Wharton.
-- Black's Law Dictionary
Legal Definition
Lat. After; occurring in a report or a text-book, is used to send the reader to a subsequent part of the book.
-- Black's Law Dictionary
Legal Definition
To attach a notice to a post or other conspicuous place; to mail a letter; after; afterward.
-- Ballentine's Law Dictionary