keel
n. countable C2 Proficiency US //ˈkiɫ// UK //kˈiːl// keel
n. the long piece of wood or metal along the bottom of a boat that helps it stay stable and straight in the water.
n. the longitudinal structural member along the base of a ship's hull, providing stability and structural integrity. In botany, refers to the two lowest petals of a pea flower that are joined together.
The ship's keel hit a rock in the shallow water.
The shipwright inspected the keel for damage before the vessel was cleared for its maiden voyage across the Atlantic.
By lowering the heavy keel, the designers ensured the yacht would remain upright even when subjected to the forceful lateral pressures of a gale-force wind.
Usage
Often used in the idiom 'on an even keel' to describe a stable or calm situation.