belly vs embryo

belly

noun
  • The womb. 

  • 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 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. 

embryo

noun
  • In the reproductive cycle, the stage after the fertilization of the egg that precedes the development into a fetus. 

  • A rudimentary plant contained in the seed. 

  • In viviparous animals, the young animal's earliest stages in the mother's body 

  • The beginning; the first stage of anything. 

  • In humans, usually the cell growth up to the end of the seventh week in the mother's body 

  • An organism in the earlier stages of development before it emerges from the egg, or before metamorphosis. 

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