guarantee vs undertake

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. 

undertake

verb
  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

  • To take upon oneself; to start, to embark on (a specific task etc.). 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

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