bravery vs nightmare

bravery

noun
  • Being brave, courageousness. 

  • A brave act. 

  • Splendor, magnificence. 

nightmare

verb
  • To have a nightmare. 

noun
  • Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure. 

  • A very bad or frightening dream. 

  • A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis. 

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