The Collaborative International Dictionary of English v.0.48:

Convulse \Con*vulse"\, v. t. [imp. & p. p. Convulsed; p. pr. &
   vb. n. Convulsing.] [L. convulsus, p. p. of convellere to
   tear up, to shake; con- + vellere to pluck, pull.]
   1. To contract violently and irregulary, as the muscular
      parts of an animal body; to shake with irregular spasms,
      as in excessive laughter, or in agony from grief or pain.
      [1913 Webster]

            With emotions which checked his voice and convulsed
            his powerful frame.                   --Macaulay.
      [1913 Webster]

   2. To agitate greatly; to shake violently.
      [1913 Webster]

            The world is convulsed by the agonies of great
            nations.                              --Macaulay.

   Syn: To agitate; disturb; shake; tear; rend.
        [1913 Webster]

WordNet (r) 3.0 (2006):

convulse
    v 1: make someone convulse with laughter; "The comedian
         convulsed the crowd"
    2: be overcome with laughter
    3: move or stir about violently; "The feverish patient thrashed
       around in his bed" [syn: convulse, thresh, thresh
       about, thrash, thrash about, slash, toss,
       jactitate]
    4: shake uncontrollably; "earthquakes convulsed the countryside"
    5: cause to contract; "The spasm convulses her facial muscles"
    6: contract involuntarily, as in a spasm; "The muscles in her
       face convulsed"

Moby Thesaurus II by Grady Ward, 1.0:

119 Moby Thesaurus words for "convulse":
   afflict, agitate, agonize, ail, amuse, beat, beat up, beguile,
   bite, bloody, bug, burn, chafe, churn, churn up, claw, concuss,
   crucify, cut, delight, disarrange, discompose, disquiet, distract,
   distress, disturb, divert, embroil, enliven, entertain, excite,
   excruciate, exhilarate, ferment, fester, flurry, fracture one,
   fret, gall, give pain, gnaw, grate, grind, gripe, harrow, hurt,
   impale, inflame, inflict pain, irritate, kill, kill by inches,
   knock dead, lacerate, lancinate, loosen up, macerate, martyr,
   martyrize, nip, paddle, pain, perturb, perturbate, pierce, pinch,
   prick, prolong the agony, psych, punish, put to torture, rack,
   raise a laugh, raise a smile, rankle, rasp, recreate, refresh,
   regale, relax, rile, rip, ripple, rock, roil, roughen, rub, ruffle,
   rumple, savage, scarify, shake, shake up, slay, solace, spook,
   stab, sting, stir, stir up, swirl, throw, throw into confusion,
   tickle, titillate, torment, torture, trouble, tweak, twist,
   unsettle, upset, whip, whip up, whisk, work up, wound, wow,
   wring