fulfill vs undertake

fulfill

verb
  • To satisfy, carry out, bring to completion (an obligation, a requirement, etc.). 

  • To emotionally or artistically satisfy; to develop one's gifts to the fullest. 

  • To package, distribute, or ship goods. 

  • To obey, follow, comply with (a rule, requirement etc.). 

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 fulfill and undertake occurred in a corpus of books? (source: Google Ngram Viewer )