trepidation vs tummyache

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. 

tummyache

noun
  • Any pain in the stomach or abdomen. 

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