fantasy vs illusion

fantasy

noun
  • That which comes from one's imagination. 

  • A fantastical design. 

  • The drug gamma-hydroxybutyric acid. 

  • The literary genre generally dealing with themes of magic and the supernatural, imaginary worlds and creatures, etc. 

verb
  • To imagine; to conceive mentally. 

  • To fantasize (about). 

illusion

noun
  • A misapprehension; a belief in something that is in fact not true. 

  • Anything that seems to be something that it is not. 

  • A magician’s trick. 

  • The state of being deceived or misled. 

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