cheerfulness vs ennui

cheerfulness

noun
  • The state of being cheerful; joy. 

ennui

verb
  • To make bored or listless; to weary. 

noun
  • A gripping listlessness or melancholia caused by boredom; depression. 

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