recoil vs tremble

recoil

verb
  • To pull back, especially in disgust, horror or astonishment. 

  • To quickly push back when fired 

noun
  • A starting or falling back; a rebound; a shrinking. 

  • The energy transmitted back to the shooter from a firearm which has fired. Recoil is a function of the weight of the weapon, the weight of the projectile, and the speed at which it leaves the muzzle. 

  • An escapement in which, after each beat, the scape-wheel recoils slightly. 

  • The state or condition of having recoiled. 

tremble

verb
  • To fear; to be afraid. 

  • To shake, quiver, or vibrate. 

noun
  • A shake, quiver, or vibration. 

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