hardship vs sadness

hardship

noun
  • Difficulty or trouble; hard times. 

  • A burden, a source of difficulty that could impose a barrier. 

verb
  • To treat (a person) badly; to subject to hardships. 

sadness

noun
  • The state or emotion of being sad. 

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

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