mainmast

The principal mast of a sailing vessel.

The taller mast, whether forward or aft, of a two-masted sailing vessel.

The second mast aft of a sailing ship with three or more masts.

plural The lower topmast and topgallantmasts of the mast next abaft the foremast.

Nautical, the principal mast in a ship or other vessel.

The principal mast in a ship or other vessel.

The chief, and tallest mast of a sailing ship that has more than one mast.

the chief mast of a sailing vessel with two or more masts