illusive vs oneiric

illusive

adj
  • Subject to or pertaining to an illusion, often used in the sense of an unrealistic expectation or an unreachable goal or outcome. 

oneiric

adj
  • Of or pertaining to dreams. 

  • Resembling a dream; dreamlike. 

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