espouse vs undertake

espouse

verb
  • To accept, support, or take on as one’s own (an idea or a cause). 

  • To become/get married to. 

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