grouch vs protestation

grouch

noun
  • A complaint, a grumble, a fit of ill-humor. 

  • One who is grumpy or irritable. 

verb
  • To be grumpy or irritable; to complain. 

protestation

noun
  • a formal solemn objection or other declaration 

  • A declaration in common-law pleading, by which the party interposes an oblique allegation or denial of some fact, protesting that it does or does not exist, and at the same time avoiding a direct affirmation or denial. 

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