(n)(linguistics) the placing of one linguistic element after another (as placing a modifier after the word that it modifies in a sentence or placing an affix after the base to which it is attached)
n. [ Cf. F. postposition. See Postpone. ] 1. The act of placing after, or the state of being placed after. “The postposition of the nominative case to the verb.” Mede. [ 1913 Webster ]
2. A word or particle placed after, or at the end of, another word; -- distinguished from preposition. [ 1913 Webster ]