a certain piece of timber, formed like the frustum of a cone, and used to stop a house-hole, or a breach made in the body of a ship by cannon-balls. Plugs used for the former purpose are therefore called house plugs, and those for the latter shot-plugs; and they are formed of various sizes, in proportion to the holes made by the different sizes of shot which may penetrate the ship's sides or bottom in battle. Accordingly they are always ready for this purpose.