declass vs discredit

declass

verb
  • To lower the class or social standing of. 

  • To remove from a class. 

discredit

verb
  • To harm the good reputation of a person; to cause an idea or piece of evidence to seem false or unreliable. 

noun
  • A degree of dishonour or disesteem; ill repute; reproach. 

  • A person or thing that causes harm to a reputation, as of a person, family, or institution. 

  • The state of being discredited or disbelieved. 

  • Discrediting or disbelieving. 

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