diehard vs hidebound

diehard

adj
  • Unreasonably or stubbornly resisting change. 

  • Fanatically opposing progress or reform. 

  • Complete; having no opposite opinion of anything in a particular topic of one's values; thorough of in one's beliefs. 

noun
  • A person with such an attitude. 

hidebound

adj
  • Stubborn; narrow-minded; inflexible. 

  • Having the bark so close and constricting that it impedes the growth. 

  • Bound with the hide of an animal. 

  • Having the skin adhering so closely to the ribs and back as not to be easily loosened or raised; emaciated. 

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