falsetto vs grumble

falsetto

verb
  • To sing or utter in falsetto. 

noun
  • A person who sings in falsetto. 

  • The "false" (singing) voice in any human, usually airy and lacking a purity of vowels; created by utilizing the next highest vocal folds above those used for speech and normal range singing. It is commonly confused with the head voice register. 

grumble

verb
  • To utter in a grumbling fashion. 

  • To complain; to murmur or mutter with discontent; to make ill-natured complaints in a low voice and a surly manner. 

  • To make a low, growling or rumbling noise, like a hungry stomach or certain animals. 

noun
  • A low thundering, rumbling or growling sound. 

  • The sound made by a hungry stomach. 

  • A surly complaint. 

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