Source : WordNet®

unbalance
     n 1: a state of disequilibrium (as may occur in cases of inner
          ear disease) [syn: {imbalance}, {instability}] [ant: {balance}]
     2: a state of mental disturbance and disorientation [syn: {derangement},
         {mental unsoundness}]
     v 1: throw out of balance or equilibrium; "The tax relief
          unbalanced the budget"; "The primadonna unbalances the
          smooth work in our department" [ant: {balance}]
     2: derange mentally, throw out of mental balance; make insane;
        "The death of his parents unbalanced him" [syn: {derange}]