bolsterer vs voucher

bolsterer

noun
  • One who, or that which, bolsters. 

voucher

noun
  • One who or that which vouches. 

  • A copy of a published advertisement sent by the agency to the client as proof of publication. 

  • A receipt. 

  • A mechanical device used in shops for automatically registering the amount of money drawn. 

  • A piece of paper that entitles the holder to a discount, or that can be exchanged for goods and services. 

verb
  • To establish the authenticity of; to vouch for. 

  • To provide (a beneficiary) with a voucher. 

  • To provide a vouch for (an expenditure). 

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