penitence vs qualm

penitence

noun
  • The condition of being penitent; a feeling of regret or remorse for doing wrong or sinning. 

qualm

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. 

verb
  • To have a sickly feeling. 

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