guarantee vs underwrite

guarantee

verb
  • To assume or take responsibility for a debt or other obligation. 

  • To make something certain. 

  • To give an assurance that something will be done right. 

noun
  • The person to whom a guarantee is made. 

  • A person who gives such a guarantee; a guarantor. 

  • A legal assurance of something, e.g. a security for the fulfillment of an obligation. 

  • More specifically, a written declaration that a certain product will be fit for a purpose and work correctly; a warranty 

  • Anything that assures a certain outcome. 

underwrite

verb
  • Specifically, to assume financial responsibility for something, and guarantee it against failure. 

  • To sign; to put one's name to. 

  • To support, lend support to, guarantee the basis of. 

  • To agree to pay by signing one's name; subscribe. 

  • To act as an underwriter. 

  • To write below or under; subscribe. 

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