The Collaborative International Dictionary of English v.0.48:

Aggravation \Ag`gra*va"tion\, n. [LL. aggravatio: cf. F.
   aggravation.]
   1. The act of aggravating, or making worse; -- used of evils,
      natural or moral; the act of increasing in severity or
      heinousness; something additional to a crime or wrong and
      enhancing its guilt or injurious consequences.
      [1913 Webster]

   2. Exaggerated representation.
      [1913 Webster]

            By a little aggravation of the features changed it
            into the Saracen's head.              --Addison.
      [1913 Webster]

   3. An extrinsic circumstance or accident which increases the
      guilt of a crime or the misery of a calamity.
      [1913 Webster]

   4. Provocation; irritation. [Colloq.] --Dickens.
      [1913 Webster]

WordNet (r) 3.0 (2006):

aggravation
    n 1: an exasperated feeling of annoyance [syn: aggravation,
         exasperation]
    2: unfriendly behavior that causes anger or resentment [syn:
       aggravation, irritation, provocation]
    3: action that makes a problem or a disease (or its symptoms)
       worse; "the aggravation of her condition resulted from lack
       of care" [syn: aggravation, exacerbation]

Moby Thesaurus II by Grady Ward, 1.0:

122 Moby Thesaurus words for "aggravation":
   accelerando, acceleration, adverse circumstances, adversity,
   affliction, agitation, animation, annoyance, annoyingness, arousal,
   arousing, bad news, bedevilment, beefing-up, blight, blowing up,
   blowup, bore, bother, botheration, bothersomeness, bummer, care,
   concentration, condensation, consolidation, crashing bore, cross,
   curse, deepening, devilment, difficulties, difficulty,
   disapprobation, disapproval, discontent, displeasure,
   dissatisfaction, dogging, downer, drag, electrification,
   enhancement, exacerbation, exaggeration, exasperation, excitation,
   excitement, exhilaration, explosion, fomentation, galvanization,
   harassment, hard knocks, hard life, hard lot, hardcase, hardship,
   harrying, headache, heating-up, heightening, hounding, incitement,
   inflammation, information explosion, infuriation, intensification,
   irksomeness, irritation, lathering up, magnification, molestation,
   nuisance, persecution, perturbation, peskiness, pest,
   pestiferousness, pickup, plaguesomeness, plight,
   population explosion, pother, predicament, pressure, problem,
   provocation, provokingness, redoubling, reinforcement,
   resentfulness, resentment, rigor, sea of troubles, speedup,
   steaming up, step-up, stimulation, stimulus, stirring, stirring up,
   strengthening, stress, stress of life, tightening, tiresomeness,
   trial, tribulation, trouble, troubles, troublesomeness,
   vale of tears, vexation, vexatiousness, vicissitude, wearisomeness,
   whipping up, working up, worriment, worrisomeness, worry



Bouvier's Law Dictionary, Revised 6th Ed (1856):

AGGRAVATION, crimes, torts. That which increases the enormity of a crime or
the injury of a wrong. The opposite of extenuation.
     2. When a crime or trespass has been committed under aggravating
circumstances, it is punished with more severity; and, the damages given to
vindicate the wrong are greater.



Bouvier's Law Dictionary, Revised 6th Ed (1856):

AGGRAVATION, in pleading. The introduction of matter into the declaration
which tends to increase the amount of damages, but does not affect the right
of action itself. Steph. Pl. 257; 12 Mod. 597. See 3 An. Jur. 287, 313. An
example of this is found in the case where a plaintiff declares in trespass
for entering his house, and breaking his close, and tossing his goods about;
the  entry of the house is the principal ground and foundation of the
action, and the rest is only stated by way of aggravation; 3 Wils. R. 294;
and this matter need not be proved by the plaintiff or answered by the
defendant.