certainty vs qualm

certainty

noun
  • The state of being certain. 

  • A fact or truth unquestionably established. 

  • An instance of being certain. 

qualm

verb
  • To have a sickly feeling. 

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

  • A feeling of apprehension, doubt, fear etc. 

  • A sudden sickly feeling; queasiness. 

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