mendacity vs unfaithfulness

mendacity

noun
  • The fact or condition of being untruthful; dishonesty. 

  • A deceit, falsehood, or lie. 

unfaithfulness

noun
  • The characteristic of being unfaithful; infidelity; disloyalty. 

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