the protuberant part of a cask, which is usually in the middle.-that part of a ship's hull or bottom which is broadest and most nearly flat, and on which she would rest if aground.-bilge water.-to suffer a fracture in the bilge; to spring a leak by a fracture in the bilge.-to bulge.-to fracture the bilge of, or stave in the bottom of (a ship or other vessel).-to cause to bulge.