chirl vs quiver

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

quiver

verb
  • To shake or move with slight and tremulous motion. 

noun
  • A multidigraph. 

  • A ready storage location for figurative tools or weapons. 

  • A container for arrows, crossbow bolts or darts, such as those fired from a bow, crossbow or blowgun. 

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