adjective: Of a selection, the property of having to choose explicitly to avoid or forbid something; a decision having the default option being inclusion or permission; used particularly with regard to mailing lists and advertisement.
noun: The act of opting out of something.
noun: (Britain, countable) A school or hospital that has withdrawn from local control.
noun: (television, radio, countable) A regional broadcast that other stations in the network may elect not to include.
