nightmare vs visionary

nightmare

noun
  • A very bad or frightening dream. 

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

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

verb
  • To have a nightmare. 

visionary

noun
  • An impractical dreamer. 

  • Someone who has positive ideas about the future. 

  • Someone who has visions; a seer. 

adj
  • imaginary or illusory 

  • having vision or foresight 

  • idealistic or utopian 

  • prophetic or revelatory 

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