keel
A large beam along the underside of a ship’s hull from bow to stern.
Other meanings
A rigid, flat piece of material anchored to the lowest part of the hull of a ship to give it greater control and stability.
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.
Word history
From Old Norse "kjǫlr".
Where this comes from
This definition is adapted from “keel” on Wiktionary, by its contributors, published under CC BY-SA 4.0. This page is published under the same licence.