frightful vs sickening

frightful

adj
  • Unpleasant, dreadful, awful (also used as an intensifier). 

  • Genuinely horrific, awful, or alarming. 

adv
  • Frightfully; very. 

sickening

adj
  • Causing sickness or disgust. 

  • Amazing, fantastic. 

noun
  • The act of making somebody sick. 

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