grim vs mortiferous

grim

adj
  • Disgusting; gross. 

  • Rigid and unrelenting. 

  • Ghastly or sinister. 

  • Dismal and gloomy, cold and forbidding. 

verb
  • To make grim; to give a stern or forbidding aspect to. 

mortiferous

adj
  • Causing physical death; deadly, fatal, lethal. 

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