chirl vs jounce

chirl

noun
  • A kind of musical warble. 

verb
  • To emit a low sound; to warble. 

jounce

noun
  • A movement, such as a jolt or a shake. 

  • The fourth derivative of the position vector with respect to time; the time derivative of jerk. 

verb
  • To jolt; to shake, especially by rough riding or by driving over obstructions. 

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