chirl vs hesitate

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

hesitate

verb
  • To stammer; to falter in speaking. 

  • To stop or pause respecting decision or action; to be in suspense or uncertainty as to a determination. 

  • To utter with hesitation or to intimate by a reluctant manner. 

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