keel - Dictionary Definition : Vocabulary.com

The keel of a boat is the beam that runs the length of the hull — the body of the boat — and can extend vertically into the water to provide stability.

A keel doesn't just refer to the stabilization of boats. When you're on "an even keel," you're stable and steady. On a bird, the keel (or breastbone) enables a bird to fly. On the other hand, if you keel over, you're quite the opposite, since you've just gone crashing to the floor.

PRIMARY MEANINGS OF: keel

1	n	one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability
2	v	walk as if unable to control one's movements

FULL DEFINITIONS OF: keel

1

n one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability

Types:: bilge keel
either of two lengthwise fins attached along the outside of a ship's bilge; reduces rolling

Type of:: beam
long thick piece of wood or metal or concrete, etc., used in construction

n the median ridge on the breastbone of birds that fly

Type of:: carina
any of various keel-shaped structures or ridges such as that on the breastbone of a bird or that formed by the fused petals of a pea blossom

n a projection or ridge that suggests a keel

Type of:: projection
any solid convex shape that juts out from something

2

v walk as if unable to control one's movements

Synonyms:: careen, lurch, reel, stagger, swag

Type of:: walk
use one's feet to advance; advance by steps