intervention

n. [ L. interventio an interposition: cf. F. intervention. ] [ 1913 Webster ]

1. The act of intervening; interposition. [ 1913 Webster ]

Sound is shut out by the intervention of that lax membrane. Holder. [ 1913 Webster ]

2. Any interference that may affect the interests of others; especially, of one or more states with the affairs of another; -- the intervention of one state in the affairs of another is typically unwelcome by the state being intervened in, but some cases of mediation between states may be called intervention. Opposed to nonintervention. [ 1913 Webster +PJC ]

Let us decide our quarrels at home, without the intervention, of any foreign power. Sir W. Temple. [ 1913 Webster ]

3. (Civil Law) The act by which a third person, to protect his own interest, interposes and becomes a party to a suit pending between other parties. [ 1913 Webster ]