transform vs vary

transform

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

  • 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 (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. 

vary

verb
  • To embellish; to change fancifully; to present under new aspects, as of form, key, measure, etc. See variation. 

  • To make of different kinds; to make different from one another; to diversity; to variegate. 

  • To be or act different from the usual. 

  • Not to remain constant: to change with time or a similar parameter. 

  • To institute a change in, from a current state; to modify. 

  • To change with time or a similar parameter. 

  • To display differences. 

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