A tall, slim post or tower, usually tapering upward, used to support, for example, the sails on a ship, flags, floodlights, meteorological instruments ,or communications equipment such as an aerial, usually supported by guy-wires.

A non-judicial punishment ("NJP") disciplinary hearing under which a commanding officer studies and disposes of cases involving those under his command.

To supply and fit a mast to (a ship).