carol vs chirl

carol

noun
  • A ballad or song of joy. 

  • A (usually traditional) religious or secular song sung at Christmastime. 

  • A round dance accompanied by singing. 

verb
  • To sing carols; especially to sing Christmas carols in a group. 

  • To praise or celebrate in song. 

  • To sing in a joyful manner. 

  • To sing (a song) cheerfully. 

  • To participate in a carol (a round dance accompanied by singing). 

chirl

noun
  • A kind of musical warble. 

verb
  • To emit a low sound; to warble. 

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