initiate vs pioneer

initiate

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

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

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

  • To begin; to start. 

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. 

pioneer

verb
  • To be the first to do or achieve (something), preparing the way for others to follow. 

noun
  • A member of a children’s organization operated by the Communist Party, typically in the second of three stages toward becoming an member of the Party itself. 

  • A person or other entity who is first or among the earliest in any field of inquiry, enterprise, or progress. 

  • One who goes before, as into the wilderness, preparing the way for others to follow. 

  • Some people will consider their national heroes to be pioneers of civilization. 

  • A member of any of several European organizations advocating abstinence from alcohol. 

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