bitter pill vs fizzle

bitter pill

noun
  • Used other than figuratively or idiomatically: see bitter, pill. 

fizzle

noun
  • A state of agitation or worry. 

  • Failure of an exploding nuclear bomb to meet its expected yield during testing. 

  • An abortive effort; a flop or dud. 

  • A spluttering or hissing sound. 

verb
  • To fail to generate the expected yield when exploded during testing. 

  • To decay or die off to nothing; to burn out; to end less successfully than previously hoped. 

  • To sputter or hiss. 

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