commission vs retain

commission

verb
  • To put into active service. 

  • To send or officially charge someone or some group to do something. 

  • To place an order for (often a piece of art). 

noun
  • A fee charged by an agent or broker for carrying out a transaction. 

  • The thing to be done as agent for another. 

  • The act of committing (e.g. a crime or error). 

  • A sending or mission (to do or accomplish something). 

  • An official charge or authority to do something, often used of military officers. 

  • A body or group of people, officially tasked with carrying out a particular function. 

retain

verb
  • To keep in one's pay or service. 

  • To employ by paying a retainer. 

  • To hold back (a pupil) instead of allowing them to advance to the next class or year. 

  • To keep in possession or use. 

  • To hold secure. 

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