illusionary vs notional

illusionary

adj
  • Illusory; pertaining to an illusion, or of the nature of an illusion. 

notional

adj
  • Of, containing, or being a notion; mental or imaginary. 

  • Having descriptive value as opposed to a syntactic category. 

  • Used to indicate an estimate or a reference amount 

  • Full of ideas or imaginings. 

  • Speculative, theoretical, not the result of research. 

noun
  • A fake company used as a front in espionage. 

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