chirl vs moan

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

moan

verb
  • To make a moan or similar sound. 

  • To complain; to grumble. 

  • To say in a moan, or with a moaning voice. 

  • To grieve. 

noun
  • a low, mournful cry of pain, sorrow or pleasure 

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