1.nounThe action of intervening; interfering in some course of events.
2.nounA legal motion through which a person or entity who has not been named as a party to a case seeks to have the court order that they be made a party.
3.nounAn orchestrated attempt to convince somebody with an addiction or other psychological problem to seek professional help and/or change their behavior.
4.nounAn action taken or procedure performed; an operation.