certify vs counterfeit

certify

verb
  • To authenticate or verify in writing. 

  • To attest that a product, service, organization, or person has met an official standard. 

  • To attest to (a fact) as the truth. 

counterfeit

verb
  • To falsely produce what appears to be official or valid; to produce a forged copy of. 

  • Of a turn or river card, to invalidate a player's hand by making a better hand on the board. 

adj
  • Inauthentic. 

  • False, especially of money; intended to deceive or carry appearance of being genuine. 

  • Assuming the appearance of something; deceitful; hypocritical. 

noun
  • A non-genuine article; a fake. 

  • One who counterfeits; a counterfeiter. 

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