castoff vs delusion

castoff

noun
  • Something that has been rejected or discarded; a reject. 

adj
  • discarded, rejected. 

delusion

noun
  • That which is falsely or delusively believed or propagated; false belief; error in belief. 

  • A false belief that is resistant to confrontation with actual facts. 

  • A fixed, false belief, that will not change, despite evidence to the contrary. 

  • The state of being deluded or misled, or process of deluding somebody. 

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