fatally vs frighteningly

fatally

adv
  • In a fatal manner; lethally. 

  • Ultimately, with finality or irrevocability, moving towards the demise of something. 

  • Fatedly; according to the dictates of fate or doom. 

frighteningly

adv
  • In a frightening or terrifying manner. 

  • Very; beyond usual expectation so as to cause surprise or concern. 

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