Shrink back in fear (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
recoil
(Other definitions for recoil that I've seen before include "Flinch, starts back" , "Flinch; rebound" , "Backward jerk of a gun when it's fired" , "Start back like a gun on firing" , "Spring back; flinch" .)