Porthole (fr.

embrasure) - shooting a hole through which issued a rifle barrel or running while driving a fire. This term is used in relation to land fortifications and armed vessels. Po rthole is a hole in the wall or roof of the building fortificatio n. The hole can be used for small arms or artillery. Most are in the form coinciding with the hopper interior to be able to keep a fire under the widest possible angle, while the barrel was shielded from the fire and debris from the sides.