ail vs nightmare

ail

verb
  • To be ill; to suffer; to be troubled. 

  • To cause to suffer; to trouble, afflict. (Now chiefly in interrogative or indefinite constructions.) 

noun
  • The awn of barley or other types of corn. 

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