agitate vs quell

agitate

verb
  • To disturb or excite; to perturb or stir up (a person). 

  • To cause to move with a violent, irregular action; to shake. 

quell

verb
  • To subdue, put down, or silence (someone or something); to force (someone) to submit. 

  • To die. 

  • To suppress, to put an end to (something); to extinguish. 

noun
  • A subduing. 

  • An emotion or sensation which rises suddenly. 

  • A source, especially a spring. 

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