martyr vs nightmare

martyr

noun
  • One who suffers greatly and/or constantly, even involuntarily. 

  • One who sacrifices their life, station, or something of great personal value, for the sake of principle or to sustain a cause. 

  • One who willingly accepts being put to death for adhering openly to one's religious beliefs; notably, saints canonized after martyrdom. 

verb
  • To make someone into a martyr by putting them to death for adhering to, or acting in accordance with, some belief, especially religious; to sacrifice on account of faith or profession. 

  • To persecute. 

  • To torment; to torture. 

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. 

verb
  • To have a nightmare. 

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