penance vs penitence

penance

noun
  • A voluntary self-imposed punishment for a sinful act or wrongdoing. It may be intended to serve as reparation for the act. 

  • Any instrument of self-punishment. 

  • A sacrament in some Christian churches. 

verb
  • To impose penance; to punish. 

penitence

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

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