The Collaborative International Dictionary of English v.0.48:

Disorder \Dis*or"der\, n. [Pref. dis- + order: cf. F.
   d['e]sordre.]
   1. Want of order or regular disposition; lack of arrangement;
      confusion; disarray; as, the troops were thrown into
      disorder; the papers are in disorder.
      [1913 Webster]

   2. Neglect of order or system; irregularity.
      [1913 Webster]

            From vulgar bounds with brave disorder part,
            And snatch a grace beyond the reach of art. --Pope.
      [1913 Webster]

   3. Breach of public order; disturbance of the peace of
      society; tumult. --Shak.
      [1913 Webster]

   4. Disturbance of the functions of the animal economy or of
      the soul; sickness; derangement. "Disorder in the body."
      --Locke.

   Syn: Irregularity; disarrangement; confusion; tumult; bustle;
        disturbance; disease; illness; indisposition; sickness;
        ailment; malady; distemper. See Disease.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disorder \Dis*or"der\, v. t. [imp. & p. p. Disordered; p. pr.
   & vb. n. Disordering.]
   1. To disturb the order of; to derange or disarrange; to
      throw into confusion; to confuse.
      [1913 Webster]

            Disordering the whole frame or jurisprudence.
                                                  --Burke.
      [1913 Webster]

            The burden . . . disordered the aids and auxiliary
            rafters into a common ruin.           --Jer. Taylor.
      [1913 Webster]

   2. To disturb or interrupt the regular and natural functions
      of (either body or mind); to produce sickness or
      indisposition in; to discompose; to derange; as, to
      disorder the head or stomach.
      [1913 Webster]

            A man whose judgment was so much disordered by party
            spirit.                               --Macaulay.
      [1913 Webster]

   3. To depose from holy orders. [Obs.] --Dryden.

   Syn: To disarrange; derange; confuse; discompose.
        [1913 Webster]

WordNet (r) 3.0 (2006):

disorder
    n 1: a physical condition in which there is a disturbance of
         normal functioning; "the doctor prescribed some medicine
         for the disorder"; "everyone gets stomach upsets from time
         to time" [syn: disorder, upset]
    2: a condition in which things are not in their expected places;
       "the files are in complete disorder" [syn: disorderliness,
       disorder] [ant: order, orderliness]
    3: a disturbance of the peace or of public order [ant: order]
    v 1: disturb in mind or make uneasy or cause to be worried or
         alarmed; "She was rather perturbed by the news that her
         father was seriously ill" [syn: perturb, unhinge,
         disquiet, trouble, cark, distract, disorder]
    2: bring disorder to [syn: disorder, disarray] [ant:
       order]

Moby Thesaurus II by Grady Ward, 1.0:

390 Moby Thesaurus words for "disorder":
   abnormality, acute disease, affection, afflict, affliction, affray,
   agitation, ailment, allergic disease, allergy, aloofness, amorphia,
   amorphism, amorphousness, anarchism, anarcho-syndicalism, anarchy,
   anomie, antinomianism, ataxia, atrophy, bacterial disease, badness,
   ball up, battle, battle royal, bedlam, befuddle, befuddlement,
   bewilderment, birth defect, blight, blobbiness, blur, blurriness,
   bluster, bobbery, boil, boiling, bother, botheration, brawl,
   broadness, brouhaha, bustle, capriciousness,
   cardiovascular disease, changeability, changeableness, chaos,
   choppiness, chronic disease, churn, circulatory disease,
   civil disorder, clamor, cloud, clutter, commotion, complaint,
   complication, condition, confound, confuse, confusion,
   congenital defect, conturbation, convulsion, criminal syndicalism,
   dappleness, daze, debilitate, defect, deficiency disease, deform,
   deformity, degenerative disease, derange, derangement, deviation,
   devitalize, difference, differentiation, diffusion, disability,
   disable, disarrange, disarrangement, disarray, discombobulation,
   discomfiture, discompose, discomposure, disconcertion,
   discontinuity, discourtesy, discreteness, disease, dishevel,
   disjoint, disjunction, dislocate, dislocation, disorderliness,
   disorderly conduct, disorganization, disorganize, disorientation,
   dispersal, dispersion, disquiet, disquietude, disrupt, disruption,
   disruptiveness, dissolution, distemper, distort, disturb,
   disturbance, divarication, divergence, diversification, ebullition,
   embarrassment, embroil, embroilment, endemic, endemic disease,
   endocrine disease, enervate, enfeeble, entropy, epidemic disease,
   excitement, ferment, fermentation, fever, feverishness, fidgets,
   fight, flap, flummox, flurry, fluster, flutter, flutteration, fog,
   fog up, fogginess, foment, formlessness, fracas, fray,
   free-for-all, frenzy, frowned-upon behavior, fuddle, fuddlement,
   fume, functional disease, fungus disease, fuss, fuzziness,
   gastrointestinal disease, generality, genetic disease, handicap,
   hash, haze, haziness, hereditary disease, hooliganism, horseplay,
   hospitalize, hubbub, huddle, hullabaloo, hurly-burly,
   iatrogenic disease, ill, ill-definedness, illness, imprecision,
   impropriety, inaccuracy, incapacitate, inchoateness, incoherence,
   inconsistency, inconstancy, indecisiveness, indefinableness,
   indefiniteness, indeterminateness, indispose, indisposition,
   inequality, inexactness, infectious disease, infirmity, inquietude,
   insanity, instability, invalid, irregularity, jerkiness, jitters,
   jumble, jumpiness, knock galley-west, laxity, lay up, litter,
   looseness, lynch law, maelstrom, malady, malaise, maze, melee,
   mercuriality, mess, mess up, messiness, misarrange, misarrangement,
   misbehavior, misconduct, misdemeanor, misdoing, mishmash, misrule,
   mist, mistiness, mix up, mob law, mob rule, mobocracy, moil,
   morbidity, morbus, motleyness, muddle, muddlement,
   muscular disease, muss, muss up, mutability, naughtiness,
   nerviness, nervosity, nervousness, neurological disease, nihilism,
   nonadhesion, noncohesion, nonconformism, nonconformity,
   nonsanctioned behavior, nonstandardization, nonuniformity,
   nutritional disease, obfuscate, obscuration, obscure, obscurity,
   occupational disease, ochlocracy, orderlessness, organic disease,
   pandemic disease, pandemonium, pathological condition, pathology,
   perplexity, perturb, perturbation, plant disease, pluralism,
   pother, primal chaos, protozoan disease, psychosomatic disease,
   pucker, raggedness, rebellion, reduce, respiratory disease,
   restlessness, revolution, riot, rockiness, roil, roughhouse, rout,
   row, rowdiness, rowdyism, ruffianism, ruffle, rummage, rumple,
   rumpus, scatter, scattering, scramble, scuffle, secondary disease,
   seediness, seethe, seething, separateness, shake up, shambles,
   shapelessness, shuffle, shuffling, sicken, sickishness, sickness,
   signs, snarl, stew, stir, sweat, sweepingness, swirl, swivet,
   symptomatology, symptomology, symptoms, syndicalism, syndrome,
   tangle, the pip, tizzy, to-do, tohubohu, topsy-turviness, tousle,
   trepidation, trepidity, tumble, tumult, tumultuation, turbidity,
   turbulence, turmoil, turn, twitter, unadherence, unadhesiveness,
   unclearness, unconformism, unconformity, unease, unevenness,
   unform, unhinge, unorthodoxy, unrest, unruliness, unsettle,
   unsettlement, unshape, unsteadiness, untenacity, untidiness,
   upheaval, uproar, upset, urogenital disease, vagueness, vandalism,
   variability, variation, variegation, variety, variousness,
   venial sin, versatility, vice, violence, virus disease,
   wasting disease, wavering, weaken, worm disease, wrongdoing