chirl vs judder

chirl

verb
  • To emit a low sound; to warble. 

noun
  • A kind of musical warble. 

judder

verb
  • To spasm or shake violently. 

  • To move with a stop-start motion, as if experiencing a strong resistance or when decelerating brusquely. 

noun
  • Jerky playback caused by converting between frame rates; telecine judder 

  • A spasmodic shaking. 

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