make-believe vs unimagined

make-believe

noun
  • The quality or act of pretending; acting as if something is true when in fact one knows it is not. 

  • The action of pretending or imagining that things are better than they really are. 

unimagined

adj
  • That has not been imagined. 

How often have the words make-believe and unimagined occurred in a corpus of books? (source: Google Ngram Viewer )