The Collaborative International Dictionary of English v.0.48:

Thunderstrike \Thun"der*strike`\, v. t. [imp. Thunderstruck;
   p. p. Thunderstruck, -strucken; p. pr. & vb. n.
   Thunderstriking.]
   1. To strike, blast, or injure by, or as by, lightning. [R.]
      --Sir P. Sidney.
      [1913 Webster]

   2. To astonish, or strike dumb, as with something terrible;
      -- rarely used except in the past participle.
      [1913 Webster]

            drove before him, thunderstruck.      --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

thunderstruck
    adj 1: as if struck dumb with astonishment and surprise; "a
           circle of policement stood dumbfounded by her denial of
           having seen the accident"; "the flabbergasted aldermen
           were speechless"; "was thunderstruck by the news of his
           promotion" [syn: dumbfounded, dumfounded,
           flabbergasted, stupefied, thunderstruck,
           dumbstruck, dumbstricken]

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "thunderstruck":
   agape, aghast, agog, all agog, amazed, astonished, astounded,
   at gaze, awed, awestruck, beguiled, bewildered, bewitched,
   breathless, captivated, confounded, dazed, dismayed, dumbfounded,
   dumbstruck, enchanted, enraptured, enravished, enthralled,
   entranced, fascinated, flabbergasted, floored, gaping, gauping,
   gazing, hypnotized, in awe, in awe of, lost in wonder, marveling,
   mesmerized, nonplussed, numb, open-eyed, openmouthed, overwhelmed,
   popeyed, puzzled, rapt in wonder, shocked, speechless, spellbound,
   staggered, staring, stunned, stupefied, surprised, taken aback,
   under a charm, wide-eyed, wonder-struck, wondering