churr vs croak

churr

verb
  • To make the low vocal sound of some birds. 

noun
  • A low vocal sound made by some birds. 

croak

verb
  • To make its sound. 

  • To kill someone or something. 

  • To complain; especially, to grumble; to forebode evil; to utter complaints or forebodings habitually. 

  • To die. 

  • To utter in a low, hoarse voice. 

  • To make a croak. 

noun
  • The call of a frog or toad. (see also ribbit) 

  • A faint, harsh sound made in the throat. 

  • The harsh call of various birds, such as the raven or corncrake, or other creatures. 

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