The Collaborative International Dictionary of English v.0.48:

Conclusion \Con*clu"sion\, n. [F., fr. L. conclusio. See
   Conclude.]
   1. The last part of anything; close; termination; end.
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            A fluorish of trumpets announced the conclusion of
            the contest.                          --Prescott.
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   2. Final decision; determination; result.
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            And the conclusion is, she shall be thine. --Shak.
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   3. Any inference or result of reasoning.
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   4. (Logic) The inferred proposition of a syllogism; the
      necessary consequence of the conditions asserted in two
      related propositions called premises. See Syllogism.
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            He granted him both the major and minor, but denied
            him the conclusion.                   --Addison.
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   5. Drawing of inferences. [Poetic]
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            Your wife Octavia, with her modest eyes
            And still conclusion.                 --Shak.
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   6. An experiment, or something from which a conclusion may be
      drawn. [Obs.]
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            We practice likewise all conclusions of grafting and
            inoculating.                          --Bacon.
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   7. (Law)
      (a) The end or close of a pleading, e.g., the formal
          ending of an indictment, "against the peace," etc.
      (b) An estoppel or bar by which a person is held to a
          particular position. --Wharton.
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   Conclusion to the country (Law), the conclusion of a
      pleading by which a party "puts himself upon the country,"
      i.e., appeals to the verdict of a jury. --Mozley & W.

   In conclusion.
      (a) Finally.
      (b) In short.

   To try conclusions, to make a trial or an experiment.
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            Like the famous ape,
            To try conclusions, in the basket creep. --Shak.

   Syn: Inference; deduction; result; consequence; end;
        decision. See Inference.
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WordNet (r) 3.0 (2006):

conclusion
    n 1: a position or opinion or judgment reached after
         consideration; "a decision unfavorable to the opposition";
         "his conclusion took the evidence into account"; "satisfied
         with the panel's determination" [syn: decision,
         determination, conclusion]
    2: an intuitive assumption; "jump to a conclusion"
    3: the temporal end; the concluding time; "the stopping point of
       each round was signaled by a bell"; "the market was up at the
       finish"; "they were playing better at the close of the
       season" [syn: stopping point, finale, finis, finish,
       last, conclusion, close]
    4: event whose occurrence ends something; "his death marked the
       ending of an era"; "when these final episodes are broadcast
       it will be the finish of the show" [syn: ending,
       conclusion, finish] [ant: beginning]
    5: the proposition arrived at by logical reasoning (such as the
       proposition that must follow from the major and minor
       premises of a syllogism) [syn: conclusion, ratiocination]
    6: the act of ending something; "the termination of the
       agreement" [syn: termination, ending, conclusion]
    7: a final settlement; "the conclusion of a business deal"; "the
       conclusion of the peace treaty"
    8: the last section of a communication; "in conclusion I want to
       say..." [syn: conclusion, end, close, closing,
       ending]
    9: the act of making up your mind about something; "the burden
       of decision was his"; "he drew his conclusions quickly" [syn:
       decision, determination, conclusion]