the principal piece of timber in a ship, which is usually first laid on the blocks in building.

Keel is also a name given to a low, flat-bottomed vessel, used in the river Tyne, to bring the coals down from Newcastle and the adjacent parts, in order to load the colliers for transportation.

Keel-Hauling was a punishment inflicted for various offences in the Dutch navy. It was performed by plunging the delinquent repeatedly under the ship's bottom on one side, and hoisting him up on the other, after having passed under the keel.