cimmerian vs dour

cimmerian

adj
  • perpetually dark or gloomy 

  • mentally dark; ignorant 

dour

adj
  • Expressing gloom or melancholy. 

  • Stern, harsh and forbidding. 

  • Unyielding and obstinate. 

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