crust vs ectoderm

crust

noun
  • Nerve, gall. 

  • An outer layer composed of pastry 

  • The top or bottom slice of a loaf of bread; The end piece of a loaf; The heel. 

  • The shell of crabs, lobsters, etc. 

  • The outermost layer of any terrestrial planet. 

  • The outermost layer of the lithosphere of the Earth. 

  • The external, hardened layer of certain foodstuffs, including most types of bread, fried meat, etc. 

  • A living. 

  • The bread-like base of a pizza. 

  • A more solid, dense or hard layer on a surface or boundary. 

verb
  • To cover with a crust. 

  • To form a crust. 

ectoderm

noun
  • Outermost of the three tissue layers in the embryo of a metazoan animal. Through development, it will produce the epidermis (skin) and nervous system of the adult. 

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