Source : Webster's Revised Unabridged Dictionary (1913)

Unwieldy \Un*wield"y\, a.
   Not easily wielded or carried; unmanageable; bulky;
   ponderous. ``A fat, unwieldy body of fifty-eight years old.''
   --Clarendon. -- {Un*wield"i*ly}, adv. -- {Un*wield"i*ness},
   n.

Source : WordNet®

unwieldiness
     n : trouble in carrying or managing caused by bulk or shape;
         "the movers cursed the unwieldiness of the big piano"
         [syn: {awkwardness}, {cumbersomeness}]