WordWeb Online

1. Derange mentally, throw out of mental balance; make insane
   "The death of his parents deranged him";
   - unbalance
    
2. Throw into great confusion or disorder
   "Fundamental Islamicists threaten to derange the social order in Algeria and Egypt";
   - perturb, throw out of kilter

Derived forms: deranges, deranging, deranged

Type of: craze, disarray, disorder, madden