castoff vs offal

castoff

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

adj
  • discarded, rejected. 

offal

noun
  • That which is thrown away as worthless or unfit for use; refuse; rubbish. 

  • A dead body; carrion. 

  • The internal organs of an animal, used as food. 

  • A by-product of the grain milling process, which may include bran, husks, etc. 

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