hold back vs undertake

hold back

verb
  • To act with reserve; to contain one's full measure or power. 

  • To delay the progress of, especially in school. 

  • To contain; stop. 

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