The term 'PART OF A HULL' can be described by two crossword solutions: BILGE (5 letters) and KEEL (4 letters). The BILGE is the lowest internal part of a ship's hull, usually near the waterline. It is used to collect any water that may have leaked into the hull. The KEEL is the central structural element of a ship's hull, running along the centerline from bow to stern. It provides strength and stability to the hull and helps to reduce drag when the ship is in motion.