The main curved portion of a knife blade.
The stomach.
The abdomen, especially a fat one.
The part of anything which resembles (either closely or abstractly) the human belly in protuberance or in concavity; often, the fundus (innermost part).
The womb.
The hollow part of a curved or bent timber, the convex part of which is the back.
The lower fuselage of an airplane.
To swell and become protuberant; to bulge or billow.
To cause to swell out; to fill.
To position one’s belly; to move on one’s belly.
Used other than figuratively or idiomatically: the edge of a knife.
A piece of steel sharpened to an acute edge or angle, and resting on a smooth surface, serving as the axis of motion of a pendulum, scale beam, or other piece required to oscillate with the least possible friction.
A precarious balance that could be upset by a very small force in either direction.