The term MAST is a nautical term used to describe the tall structure of a ship. It consists of a POST, a POLE, and a SPAR. The POST is a vertical support that holds the mast in place. The POLE is a long, cylindrical piece of wood or metal that runs along the length of the mast. The SPAR is a horizontal beam that helps to support the mast and provide stability. Together, these three components form the mast of a ship, which is essential for providing stability and allowing the ship to sail.