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.
The sharp edge of the blade of a knife or other cutting tool.
The forefront, or position of greatest advancement in some field.