- A large beam along the underside of a ship's hull from bow to stern.
- Sometimes, a rigid, flat piece of material anchored to the lowest part of the hull of a ship to it greater control and stability.
- Something similar to chalk or crayon used to mark pavement.
noun (wikipedia, Kepler's laws of planetary motion )
(astronomy) the three laws of planetary motion discovered by Kepler in the early 17th century