The Collaborative International Dictionary of English v.0.48:

Dismay \Dis*may"\, v. t. [imp. & p. p. Dismayed; p. pr. & vb.
   n. Dismaying.] [OE. desmaien, dismaien, OF. esmaier; pref.
   es- (L. ex) + OHG. magan to be strong or able; akin to E.
   may. In English the pref. es- was changed to dis- (L. dis-).
   See May, v. i.]
   1. To disable with alarm or apprehensions; to depress the
      spirits or courage of; to deprive or firmness and energy
      through fear; to daunt; to appall; to terrify.
      [1913 Webster]

            Be not afraid, neither be thou dismayed. --Josh. i.
                                                  9.
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            What words be these? What fears do you dismay?
                                                  --Fairfax.
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   2. To render lifeless; to subdue; to disquiet. [Obs.]
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            Do not dismay yourself for this.      --Spenser.

   Syn: To terrify; fright; affright; frighten; appall; daunt;
        dishearthen; dispirit; discourage; deject; depress. --
        To Dismay, Daunt, Appall. Dismay denotes a state
        of deep and gloomy apprehension. To daunt supposes
        something more sudden and startling. To appall is the
        strongest term, implying a sense of terror which
        overwhelms the faculties.
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              So flies a herd of beeves, that hear, dismayed,
              The lions roaring through the midnight shade.
                                                  --Pope.
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              Jove got such heroes as my sire, whose soul
              No fear could daunt, nor earth nor hell control.
                                                  --Pope.
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              Now the last ruin the whole host appalls;
              Now Greece has trembled in her wooden walls.
                                                  --Pope.
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The Collaborative International Dictionary of English v.0.48:

Dismay \Dis*may"\, v. i.
   To take dismay or fright; to be filled with dismay. [Obs.]
   --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Dismay \Dis*may"\, n. [Cf. OF. esmai, F. ['e]moi. See Dismay,
   v. t.]
   1. Loss of courage and firmness through fear; overwhelming
      and disabling terror; a sinking of the spirits;
      consternation.
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            I . . . can not think of such a battle without
            dismay.                               --Macaulay.
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            Thou with a tiger spring dost leap upon thy prey,
            And tear his helpless breast, o'erwhelmed with wild
            dismay.                               --Mrs.
                                                  Barbauld.
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   2. Condition fitted to dismay; ruin. --Spenser.

   Syn: Dejection; discouragement; depression; fear; fright;
        terror; apprehension; alarm; affright.
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WordNet (r) 3.0 (2006):

dismay
    n 1: the feeling of despair in the face of obstacles [syn:
         discouragement, disheartenment, dismay]
    2: fear resulting from the awareness of danger [syn: alarm,
       dismay, consternation]
    v 1: lower someone's spirits; make downhearted; "These news
         depressed her"; "The bad state of her child's health
         demoralizes her" [syn: depress, deject, cast down,
         get down, dismay, dispirit, demoralize,
         demoralise] [ant: elate, intoxicate, lift up, pick
         up, uplift]
    2: fill with apprehension or alarm; cause to be unpleasantly
       surprised; "I was horrified at the thought of being late for
       my interview"; "The news of the executions horrified us"
       [syn: dismay, alarm, appal, appall, horrify]

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "dismay":
   abash, abject fear, affright, agitate, agitation, alarm, anxiety,
   appall, apprehension, astound, awe, bewilder, blue funk, bother,
   cold feet, confound, consternation, cow, cowardice, daunt,
   discomfit, discomfort, discompose, disconcert, discourage,
   dishearten, disquiet, distress, dread, dumbfound, embarrass, faze,
   fear, flummox, flurry, fluster, fright, frighten, funk, grieve,
   horrification, horrify, horror, intimidate, lament, moider, mourn,
   mystify, nonplus, pain, panic, panic fear, perplex, perturb,
   petrify, phobia, pother, put off, put out, puzzle, rattle, scare,
   shake, shock, sorrow, stampede, startle, take aback, terrify,
   terror, trepidation, unhinge, unholy dread, unnerve, unsettle,
   upset