initiate vs undertake

initiate

verb
  • To begin; to start. 

  • To instruct in the rudiments or principles; to introduce. 

  • To do the first act; to perform the first rite; to take the initiative. 

  • To confer membership on; especially, to admit to a secret order with mysterious rites or ceremonies. 

noun
  • One who is oriented in and familiar with a topic or subject; especially, one who is an expert in it. 

  • A new member of an organization. 

  • One who has been through a ceremony of initiation. 

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