Acherontic vs dismal

Acherontic

adj
  • Lacking joy and comfort; nearing death. 

  • Of, pertaining to or resembling Acheron (one of the rivers located in the underworld according to ancient Greek mythology). 

  • Of or pertaining to hell. 

dismal

adj
  • Causing despair; gloomy and bleak. 

  • Depressing, dreary, cheerless. 

  • Disastrous, calamitous 

  • Disappointingly inadequate. 

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