belly vs middle

belly

noun
  • The part of anything which resembles (either closely or abstractly) the human belly in protuberance or in concavity; often, the fundus (innermost part). 

  • The stomach. 

  • The main curved portion of a knife blade. 

  • The abdomen, especially a fat one. 

  • 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. 

verb
  • 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. 

middle

noun
  • The central part of a human body; the waist. 

  • A centre, midpoint. 

  • The part between the beginning and the end. 

  • The middle stump. 

  • The middle voice. 

adj
  • Pertaining to the middle voice. 

  • Located in the middle; in between. 

  • Central. 

How often have the words belly and middle occurred in a corpus of books? (source: Google Ngram Viewer )