blackness vs repining

blackness

noun
  • The quality of being evil or dismal. 

  • The state of being of African descent. 

  • The state or quality of being black in colour. 

  • The experiences and culture of African-American people. 

repining

noun
  • The act of fretting or feeling discontent or of murmuring. 

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