stomachache vs trepidation

stomachache

noun
  • A pain in the abdomen, often caused by indigestion. (The pain is usually lower than the stomach and related to the intestines.) 

trepidation

noun
  • An involuntary trembling, sometimes an effect of paralysis, but usually caused by terror or fear. 

  • A fearful state; a state of concern or hesitation. 

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