chirl vs stumble

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

stumble

verb
  • To mislead; to confound; to cause to err or to fall. 

  • To cause to stumble or trip. 

  • To trip or fall; to walk clumsily. 

  • To make a mistake or have trouble. 

  • To strike or happen (upon a person or thing) without design; to fall or light by chance; with on, upon, or against. 

noun
  • An error or blunder. 

  • A fall, trip or substantial misstep. 

  • A clumsy walk. 

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