initiate vs introduce

initiate

verb
  • 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. 

  • 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. 

introduce

verb
  • To bring (something) into practice. 

  • To cause (someone) to be acquainted (with someone else). 

  • To add (something) to a system, a mixture, or a container. 

  • To make (something or someone) known by formal announcement or recommendation. 

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