nightmare vs quaver

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. 

quaver

verb
  • To utter quaveringly. 

  • To shake in a trembling manner. 

  • To use the voice in a trembling manner, as in speaking or singing. 

noun
  • A trembling shake. 

  • an eighth note, drawn as a crotchet (quarter note) with a tail. 

  • A trembling of the voice, as in speaking or singing. 

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