recoil

intransitive verb

1. 1. to draw back, fall back, or stagger back; retreat
   2. to start or shrink back, as in fear, surprise, or disgust
2. to fly back when released, as a spring, or kick back when fired, as a gun
3. to return to or as to the starting point or source; react (on or upon)

noun

1. the act of recoiling
2. the state of having recoiled; reaction
3. the distance through which a gun, spring, etc. recoils