What does "scupper" mean?

Scupper: An opening cut through the waterway and bulwarks of a ship, so that water falling on deck may flow overboard; -- called also scupper hole. Scupper hose (Naut.), a pipe of leather, canvas, etc., attached to the mouth of the scuppers, on the outside of a vessel, to prevent the water from entering. Totten. -- Scupper nail (Naut.), a nail with a very broad head, for securing the edge of the hose to the scupper. -- Scupper plug (Naut.), a plug to stop a scupper. Totten.