morbid vs pessimistic

morbid

adj
  • Suggesting the horror of death; macabre or ghoulish. 

  • Of, or relating to disease. 

  • Grisly or gruesome. 

  • Taking an interest in, or fixating on, unhealthy or unwholesome subjects such as death, decay, disease. 

pessimistic

adj
  • Pertaining to the worst-case scenario. 

  • Marked by pessimism and little hopefulness; expecting the worst. 

  • Taking out exclusive locks on data to prevent conflicts with other processes that might modify it. 

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