bad humour vs grievance

bad humour

noun
  • irritability or surliness 

  • a state of irritability or surliness 

grievance

noun
  • A complaint or annoyance. 

  • A formal complaint, especially in the context of a unionized workplace. 

  • Feelings of being wronged; outrage. 

  • A wrong or hardship suffered, which is the grounds of a complaint. 

  • Violation of regulations or objectionable behavior. 

  • Something which causes grief. 

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