chirl vs descant

chirl

noun
  • A kind of musical warble. 

verb
  • To emit a low sound; to warble. 

descant

noun
  • A counterpoint melody sung or played above the theme. 

  • A lengthy discourse on a subject. 

verb
  • To sing or play a descant. 

  • To discuss at length. 

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