The Collaborative International Dictionary of English v.0.48:

Mishandle \Mis*han"dle\, v. t.
   To handle ill or wrongly; to maltreat.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mishandle
    v 1: make a mess of, destroy or ruin; "I botched the dinner and
         we had to eat out"; "the pianist screwed up the difficult
         passage in the second movement" [syn: botch, bodge,
         bumble, fumble, botch up, muff, blow, flub,
         screw up, ball up, spoil, muck up, bungle,
         fluff, bollix, bollix up, bollocks, bollocks up,
         bobble, mishandle, louse up, foul up, mess up,
         fuck up]
    2: manage badly or incompetently; "The funds were mismanaged"
       [syn: mismanage, mishandle, misconduct]