The Collaborative International Dictionary of English v.0.48:

Exclamation \Ex`cla*ma"tion\, n. [L. exclamatio: cf. F.
   exclamation.]
   1. A loud calling or crying out; outcry; loud or emphatic
      utterance; vehement vociferation; clamor; that which is
      cried out, as an expression of feeling; sudden expression
      of sound or words indicative of emotion, as in surprise,
      pain, grief, joy, anger, etc.
      [1913 Webster]

            Exclamations against abuses in the church. --Hooker.
      [1913 Webster]

            Thus will I drown your exclamations.  --Shak.
      [1913 Webster]

            A festive exclamation not unsuited to the occasion.
                                                  --Trench.
      [1913 Webster]

   2. (Rhet.) A word expressing outcry; an interjection; a word
      expressing passion, as wonder, fear, or grief.
      [1913 Webster]

   3. (Print.) A mark or sign by which outcry or emphatic
      utterance is marked; thus [!]; -- called also exclamation
      point.
      [1913 Webster]

WordNet (r) 3.0 (2006):

exclamation
    n 1: an abrupt excited utterance; "she gave an exclamation of
         delight"; "there was much exclaiming over it" [syn:
         exclamation, exclaiming]
    2: a loud complaint or protest or reproach
    3: an exclamatory rhetorical device; "O tempore! O mores" [syn:
       ecphonesis, exclamation]

Moby Thesaurus II by Grady Ward, 1.0:

45 Moby Thesaurus words for "exclamation":
   Parthian shot, address, affirmation, allegation, answer,
   apostrophe, assertion, averment, bellow, blurt, call, comment,
   crack, cry, declaration, dictum, ecphonesis, ejaculation,
   expletive, expression, greeting, holler, interjection, mention,
   note, observation, outburst, outcry, phrase, position,
   pronouncement, question, reflection, remark, say, saying, sentence,
   shout, statement, subjoinder, thought, utterance, vociferation,
   word, yell