Merriam-Webster Collegiate Dictionary - recoil

 I. intransitive verb  Etymology: Middle English reculen, ~en, from Anglo-French reculer, recuiler, from re- + cul backside — more at culet  Date: 14th century  1.  a. to fall back under pressure  b. to shrink back physically or emotionally  2. to spring back to or as if to a starting point ; rebound  3. obsolete degenerate Synonyms:  ~, shrink, flinch, wince, blench, quail mean to draw back in fear or distaste. ~ implies a start or movement away through shock, fear, or disgust ~ed at the suggestion of stealing. shrink suggests an instinctive ~ through sensitiveness, scrupulousness, or cowardice shrank from the unpleasant truth. flinch implies a failure to endure pain or face something dangerous or frightening with resolution faced her accusers without flinching. wince suggests a slight involuntary physical reaction (as a start or ~ing) winced in pain. blench implies fainthearted flinching stood their ground without blenching. quail suggests shrinking and cowering in fear quailed before the apparition.  II. noun  Date: 14th century  1. the act or action of ~ing; especially the kickback of a gun upon firing  2. reaction the ~ from the rigors of Calvinism — Edmund Wilson