counterfeit vs duplicate

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. 

noun
  • A non-genuine article; a fake. 

  • One who counterfeits; a counterfeiter. 

adj
  • Inauthentic. 

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

  • Assuming the appearance of something; deceitful; hypocritical. 

duplicate

verb
  • To make a copy of. 

  • To produce something equal to. 

  • To do repeatedly; to do again. 

adj
  • In which the hands of cards, tiles, etc. are preserved between rounds to be played again by other players. 

  • Being the same as another; identical, often having been copied from an original. 

noun
  • One that resembles or corresponds to another; an identical copy. 

  • A pawnbroker's ticket, which must be shown when redeeming a pledged item. 

  • The game of duplicate bridge. 

  • The game of duplicate Scrabble. 

  • A biological specimen that was gathered alongside another specimen and represents the same species. 

  • An original instrument repeated; a document which is the same as another in all essential particulars, and differing from a mere copy in having all the validity of an original 

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