abdomen vs middle-age spread

abdomen

noun
  • The belly, or that part of the body between the thorax and the pelvis, not including the back; or in some lower vertebrates, the portion between the cardiac and caudal regions. 

  • The posterior section of the body, behind the thorax, in insects, crustaceans, and other Arthropoda. 

  • The cavity of the belly, which is lined by the peritoneum, and contains the viscera; often restricted in humans to the part between the diaphragm and the commencement of the pelvis, the remainder being called the pelvic cavity. 

middle-age spread

noun
  • Belly fat that develops in middle age. 

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