tremble vs twerk

tremble

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

noun
  • A shake, quiver, or vibration. 

twerk

verb
  • To twitch or jerk. 

  • To move the body in a sexually suggestive twisting or gyrating fashion, especially as a dance. 

noun
  • A fitful movement similar to a twitch or jerk. 

  • A dance involving sexual movements of the hips and buttocks. 

  • An abrupt call, such as that made by the California quail. 

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