get going vs undertake

get going

verb
  • To begin or commence. 

  • To talk passionately without interruption. 

  • To cause someone to talk passionately without interruption. 

  • To cry or bawl loudly. 

  • To arouse sexually. 

  • To leave, or depart. 

  • To excite intellectually. 

undertake

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

  • 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. 

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

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