meditation vs nightmare

meditation

noun
  • A devotional exercise of, or leading to contemplation. 

  • A contemplative discourse, often on a religious or philosophical subject. 

  • Careful and thorough thought. 

  • A musical theme treated in a meditative manner. 

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 meditation and nightmare occurred in a corpus of books? (source: Google Ngram Viewer )