noun A large beam along the underside of a ship’s hull from bow to stern.
noun A rigid, flat piece of material anchored to the lowest part of the hull of a ship to give it greater control and stability.
noun In a dirigible, a construction similar in form and use to a ship's keel; in an aeroplane, a fin or fixed surface employed to increase stability and to hold the machine to its course.
noun The rigid bottom part of something else, especially an iceberg.
noun A type of flat-bottomed boat.
noun The periphery of a whorl extended to form a more or less flattened plate; a prominent spiral ridge.
noun The two lowest petals of the corolla of a papilionaceous flower, united and enclosing the stamens and pistil; a carina.
noun The extension of a bird's sternum to which pectoral muscles attach.