frolic vs sadness

frolic

verb
  • To make merry; to have fun; to romp; to behave playfully and uninhibitedly. 

noun
  • Gaiety; merriment. 

  • A playful antic. 

sadness

noun
  • The state or emotion of being sad. 

  • An event in one's life that causes sadness. 

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