neb vs oral cavity

neb

noun
  • A person's nose. 

  • A nib, as of a pen. 

  • A bird's beak or bill. 

  • The peak of a flat cap. 

  • The nose or snout of an animal, now especially of a fish. 

  • A projecting extremity; a point or sharp projection. 

oral cavity

noun
  • The cavity of the mouth, especially the part of the mouth behind the gums and teeth that is bounded above by the hard and soft palates and below by the tongue and by the mucous membrane connecting it with the inner part of the mandible. 

  • The hollow on the lower surface of the head from which the proboscis protrudes. 

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