1) Opening for firing 
The opening in the side of the ship or in a turret through which the gun fires or protrudes.
The opening in the side of the ship or in a turret through which the gun fires or protrudes.
Opening in a ship's sides or bulwarks for running out the cannon. Most were covered with a hinged lid.
(from the article `naval ship`) ...of England created the first true oceangoing battle fleet. The `king`s ships` carried many guns, but most of these weapons were small ...
a hole, sometimes with an opening shutter, for a cannon to fire through
an aperture, as in a protective wall or the side of a ship, through which a gun can be aimed and fired.