conceal vs falsify

conceal

verb
  • To hide something from view or from public knowledge, to try to keep something secret. 

falsify

verb
  • To misrepresent. 

  • To alter so as to make false; to make incorrect. 

  • To prove to be false. 

  • To counterfeit; to forge. 

  • To show (an item of charge inserted in an account) to be wrong. 

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