belly vs innard

belly

• The stomach. 

• The main curved portion of a knife blade. 

• 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. 

innard

• Entrail; gut; intestine.