Bilge

Bilge (sometimes spelled BULGE) is the part of the bottom of a ship nearest to the keel, and always more nearly horizontal than vertical. A ship usually rests on the keel and one side of the bilge when aground. The name of bilge-water is given to water which finds its way into the bilge or lowest part of a ship, and which, when not drawn off by the pump, becomes dirty and offensive.