The Collaborative International Dictionary of English v.0.48:

Disturb \Dis*turb"\, v. t. [imp. & p. p. Disturbed; p. pr. &
   vb. n. Disturbing.] [OE. desturben, destourben, OF.
   destorber, desturber, destourber, fr. L. disturbare,
   disturbatum; dis- + turbare to disturb, trouble, turba
   disorder, tumult, crowd. See Turbid.]
   1. To throw into disorder or confusion; to derange; to
      interrupt the settled state of; to excite from a state of
      rest.
      [1913 Webster]

            Preparing to disturb
            With all-cofounding war the realms above. --Cowper.
      [1913 Webster]

            The bellow's noise disturbed his quiet rest.
                                                  --Spenser.
      [1913 Webster]

            The utmost which the discontented colonies could do,
            was to disturb authority.             --Burke.
      [1913 Webster]

   2. To agitate the mind of; to deprive of tranquillity; to
      disquiet; to render uneasy; as, a person is disturbed by
      receiving an insult, or his mind is disturbed by envy.
      [1913 Webster]

   3. To turn from a regular or designed course. [Obs.]
      [1913 Webster]

            And disturb
            His inmost counsels from their destined aim.
                                                  --Milton.

   Syn: To disorder; disquiet; agitate; discompose; molest;
        perplex; trouble; incommode; ruffle.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Disturb \Dis*turb"\, n.
   Disturbance. [Obs.] --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

disturb
    v 1: move deeply; "This book upset me"; "A troubling thought"
         [syn: disturb, upset, trouble]
    2: change the arrangement or position of [syn: agitate, vex,
       disturb, commove, shake up, stir up, raise up]
    3: tamper with; "Don't touch my CDs!" [syn: touch, disturb]
    4: destroy the peace or tranquility of; "Don't interrupt me when
       I'm reading" [syn: interrupt, disturb]
    5: damage as if by shaking or jarring; "Don't disturb the
       patient's wounds by moving him too rapidly!"

Moby Thesaurus II by Grady Ward, 1.0:

188 Moby Thesaurus words for "disturb":
   abash, addle, addle the wits, affect, afflict, aggravate, agitate,
   ail, alarm, annoy, badger, bait, ball up, be at, be the matter,
   beat, beat up, becloud, bedazzle, bedevil, befuddle, beset,
   bewilder, bother, bristle, brown off, bug, bullyrag, burden,
   burn up, cancel, change, chivy, churn, churn up, cloud,
   complicate matters, concern, confound, confuse, convulse, damage,
   daze, dazzle, derange, destroy, devil, disarrange, disarray,
   discombobulate, discomfit, discomfort, discommode, discompose,
   disconcert, dishevel, dislocate, dismay, disorder, disorganize,
   disorient, displace, disquiet, disrupt, distemper, distract,
   distress, dog, electrify, embarrass, embroil, entangle, exasperate,
   excite, exercise, fash, ferment, flummox, flurry, fluster, flutter,
   fog, frazzle, fret, frighten, fuddle, fuss, get, give concern,
   gripe, harass, harm, harry, hassle, heckle, hector, hound,
   humiliate, incommode, inconvenience, interfere, interfere with,
   intermeddle, interrupt, irk, irritate, jar, jolt, jumble,
   knock galley-west, load with care, maze, meddle, mess up, miff,
   mist, mix up, moider, molest, mortify, move, muddle, nag, needle,
   negate, nettle, nudzh, paddle, peeve, perplex, persecute, perturb,
   perturbate, pester, pick on, pique, plague, pluck the beard,
   pother, provoke, psych, put off, put out, put to it, puzzle,
   raise hell, rattle, remove, replace, ride, rile, ripple, rock,
   roil, roughen, ruffle, ruin, rumple, scare, shake, shake up, shift,
   ship, shock, spook, stagger, stir, stir up, swirl, tamper, tease,
   terrify, throw, throw into confusion, torment, transfer, trouble,
   try the patience, tweak the nose, unhinge, unsettle, upset, vex,
   whip, whip up, whisk, work up, worry