The Collaborative International Dictionary of English v.0.48:

Aggravate \Ag"gra*vate\, v. t. [imp. & p. p. Aggravated; p.
   pr. & vb. n. Aggravating.] [L. aggravatus, p. p. of
   aggravare. See Aggrieve.]
   1. To make heavy or heavier; to add to; to increase. [Obs.]
      "To aggravate thy store." --Shak.
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   2. To make worse, or more severe; to render less tolerable or
      less excusable; to make more offensive; to enhance; to
      intensify. "To aggravate my woes." --Pope.
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            To aggravate the horrors of the scene. --Prescott.
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            The defense made by the prisoner's counsel did
            rather aggravate than extenuate his crime.
                                                  --Addison.
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   3. To give coloring to in description; to exaggerate; as, to
      aggravate circumstances. --Paley.
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   4. To exasperate; to provoke; to irritate. [Colloq.]
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            If both were to aggravate her parents, as my brother
            and sister do mine.                   --Richardson
                                                  (Clarissa).
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   Syn: To heighten; intensify; increase; magnify; exaggerate;
        provoke; irritate; exasperate.
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WordNet (r) 3.0 (2006):

aggravate
    v 1: make worse; "This drug aggravates the pain" [syn: worsen,
         aggravate, exacerbate, exasperate] [ant:
         ameliorate, amend, better, improve, meliorate]
    2: exasperate or irritate [syn: exacerbate, exasperate,
       aggravate]