n. A being, placing, or coming between, as of something that obstructs or interferes; intervention.n. Intervenient agency; agency between parties; interference; mediation.n. That which is interposed.n. Synonyms Interposition, Interference, Intervention, Mediation. The first three of these have the same differences as the corresponding verbs. (See interpose.) Intervention and interference are used of persons or things; interposition and mediation only of persons. Mediation is a friendly act performed in order to reconcile those who are estranged or opposed: as, France refused all offers of mediation, and seemed bent upon war. The word mediation is rarely used where the friendly interposition is not consented to by the parties to the Controversy, or where it is not at least in some degree successful.n. In mineralogy, same as inclusion, 2.