arousal vs nightmare

arousal

noun
  • Arousal from sleep or hibernation. 

  • A physiological and psychological state of being awake or reactive to stimuli, including elevated heart rate and blood pressure and a condition of sensory alertness, mobility and readiness to respond. 

  • The act of arousing or the state of being aroused. 

  • Sexual arousal. 

nightmare

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

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

  • A very bad or frightening dream. 

verb
  • To have a nightmare. 

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