discard vs jettison

discard

verb
  • To throw away, to reject. 

  • To make a discard; to throw out a card. 

  • To dismiss from employment, confidence, or favour; to discharge. 

noun
  • A temporary variable used to receive a value of no importance and unable to be read later. 

  • Anything discarded. 

  • A discarded playing card in a card game. 

jettison

verb
  • To let go or get rid of as being useless or defective. 

  • To eject from a boat, submarine, aircraft, spaceship or hot-air balloon, so as to lighten the load. 

noun
  • Items that have been or are about to be ejected from a boat or balloon. 

  • The action of jettisoning items. 

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