derm vs integument

derm

noun
  • The integument of animal; the skin. 

  • Synonym of dermis. 

  • Guts, entrails. 

integument

noun
  • An outer protective covering such as the feathers or skin of an animal, a rind or shell. 

  • The outer layer of an ovule, which develops into the seed coat. 

  • A shell or other outer protective layer. 

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