derma vs parchment

derma

noun
  • The inner layer of the skin. 

  • A Jewish dish of roast or boiled seasoned meat and flour etc. in a casing, especially kishke. 

parchment

noun
  • The creamy to tanned color of parchment. 

  • A document made on such material. 

  • Material, made from the polished skin of a calf, sheep, goat or other animal, used like paper for writing. 

  • The envelope of the coffee grains, inside the pulp. 

  • Stiff paper imitating that material. 

  • A diploma (traditionally written on parchment). 

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