Intervention

Part of speech: noun (n.)

1. The act of intervening; interposition. Sound is shut out by the intervention of that lax membrane. Holder.

2. Any interference that may affect the interests of others; especially, of one or more states with the affairs of another; mediation. Let us decide our quarrels at home, without the intervention, of any foreign power. Sir W. Temple.

3. The act by which a third person, to protect his own interest, interposes and becomes a party to a suit pending between other parties.