Source : Webster's Revised Unabridged Dictionary (1913)

Disproportionate \Dis`pro*por"tion*ate\, a.
   Not proportioned; unsymmetrical; unsuitable to something else
   in bulk, form, value, or extent; out of proportion;
   inadequate; as, in a perfect body none of the limbs are
   disproportionate; it is wisdom not to undertake a work
   disproportionate means. -- {Dis`pro*por"tion*ate*ly}, adv. --
   {Dis`pro*por"tion*ate*ness}, n.

Source : WordNet®

disproportionate
     adj 1: out of proportion [syn: {disproportional}] [ant: {proportionate}]
     2: not proportionate