cuticle vs ectoderm

cuticle

noun
  • The outermost layer of the skin of vertebrates; the epidermis. 

  • A noncellular protective covering outside the epidermis of many invertebrates and plants. 

  • The strip of hardened skin at the base and sides of a fingernail or toenail. 

  • A thin skin formed on the surface of a liquid. 

  • Dead or cornified epidermis. 

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 cuticle and ectoderm occurred in a corpus of books? (source: Google Ngram Viewer )