Source : Webster's Revised Unabridged Dictionary (1913)

Flinch \Flinch\, n.
   The act of flinching.

Flinch \Flinch\, v. i. [imp. & p. p. {Flinched}; p. pr. & vb. n.
   {Flinching}.] [Prob. fr. OE. flecchen to waver, give way, F.
   fl['e]chir, fr. L. flectere to bend; but prob. influenced by
   E. blench. Cf. {Flex}.]
   1. To withdraw from any suffering or undertaking, from pain
      or danger; to fail in doing or perserving; to show signs
      of yielding or of suffering; to shrink; to wince; as, one
      of the parties flinched from the combat.

            A child, by a constant course of kindness, may be
            accustomed to bear very rough usage without
            flinching or complaining.             --Locke.

   2. (Croquet) To let the foot slip from a ball, when
      attempting to give a tight croquet.

Source : WordNet®

flinch
     n : a reflex response to sudden pain [syn: {wince}]
     v : draw back, as with fear or pain; "she flinched when they
         showed the slaughtering of the calf" [syn: {squinch}, {funk},
          {cringe}, {shrink}, {wince}, {recoil}, {quail}]