castoff vs useless

castoff

adj
  • discarded, rejected. 

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

useless

adj
  • Unhelpful, not useful; pointless (of an action). 

  • Unable to do well at a particular task or thing. Useless is mildly insulting. 

  • Without use or possibility to be used. 

  • Good-for-nothing; not dependable. 

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