The Collaborative International Dictionary of English v.0.48:

Uncontrollable \Un`con*trol"la*ble\, a.
   1. Incapable of being controlled; ungovernable; irresistible;
      as, an uncontrollable temper; uncontrollable events.
      [1913 Webster]

   2. Indisputable; irrefragable; as, an uncontrollable maxim;
      an uncontrollable title. [R.] --Swift.
      [1913 Webster] -- Un`con*trol"la*ble*ness, n. --
      Un`con*trol"la*bly, adv.
      [1913 Webster]

WordNet (r) 3.0 (2006):

uncontrollable
    adj 1: difficult to solve or alleviate; "uncontrollable pain"
           [syn: uncontrollable, unmanageable]
    2: of persons; "the little boy's parents think he is spirited,
       but his teacher finds him unruly" [syn: indocile,
       uncontrollable, ungovernable, unruly]
    3: incapable of being controlled or managed; "uncontrollable
       children"; "an uncorrectable habit" [syn: uncontrollable,
       uncorrectable, unmanageable]
    4: impossible to repress or control; "an irrepressible
       chatterbox"; "uncontrollable laughter" [syn: irrepressible,
       uncontrollable]

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "uncontrollable":
   Dionysiac, abandoned, amok, bacchic, bellowing, berserk,
   beyond control, breachy, carried away, certain, contumacious,
   corybantic, defiant, delirious, demoniac, desperate, distracted,
   ecstatic, enraptured, fated, fateful, feral, ferocious, fierce,
   fractious, frantic, frenetic, frenzied, fulminating, furious,
   haggard, hog-wild, howling, hysterical, in a transport,
   in hysterics, incorrigible, indefeasible, indocile, indomitable,
   ineluctable, inescapable, inevasible, inevitable, inexorable,
   inflexible, insuppressible, intoxicated, intractable,
   irrepressible, irresistible, irrevocable, like one possessed, mad,
   madding, maenadic, maniac, maniacal, necessary, obstreperous,
   orgasmic, orgiastic, out of hand, possessed, rabid, raging,
   ramping, ranting, raving, raving mad, ravished, recalcitrant,
   refractory, relentless, resistant, resisting, resistless, restive,
   roaring, running mad, running wild, shrewish, stark-raving mad,
   storming, sure, sure as death, sure as fate, transported,
   unavoidable, unbiddable, undeflectable, undisciplined,
   ungovernable, unmalleable, unmanageable, unmoldable, unpreventable,
   unruly, unstoppable, unsubmissive, unyielding, violent, wild,
   wild-eyed, wild-looking