apostasy vs castoff

apostasy

noun
  • The renunciation of a belief or set of beliefs. 

  • Specifically, the renunciation of one's religion or faith. 

castoff

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

adj
  • discarded, rejected. 

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