specimen vs wild card

specimen

noun
  • A postage stamp sent to postmasters and postal administrations so that they are able to identify valid stamps and to avoid forgeries 

  • An eligible man. 

  • An individual instance that represents a class; an example. 

  • A banknote printed for distribution to central banks to aid in the recognition of banknotes from a country other than their own 

  • A sample, especially one used for diagnostic analysis. 

wild card

noun
  • A card that can be assigned any value or used to substitute for any needed card. 

  • A competitor or team that is allowed to compete in a tournament despite not reaching the normal standards to qualify for inclusion. 

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