qualm vs unease

qualm

noun
  • A sudden sickly feeling; queasiness. 

  • A prick of the conscience; a moral scruple, a pang of guilt. 

  • A feeling of apprehension, doubt, fear etc. 

verb
  • To have a sickly feeling. 

unease

noun
  • Trouble; misery; a feeling of disquiet or concern. 

verb
  • To make uneasy or uncomfortable 

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