retain vs transform

retain

verb
  • 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 one's pay or service. 

  • To keep in possession or use. 

  • To hold secure. 

transform

verb
  • To undergo a transformation; to change in appearance or character. 

  • To change greatly the appearance or form of. 

  • To subject to the action of a transformer. 

  • To subject to a transformation; to change into another form without altering the value. 

  • To subject (a cell) to transformation. 

  • To change the nature, condition or function of; to change in nature, disposition, heart, character, etc.; to convert. 

noun
  • A transform fault. 

  • An operation (often an integration) that converts one function into another. 

  • A function so produced. 

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