WordNet (r) 3.0 (2006):

Creutzfeldt-Jakob disease
    n 1: rare (usually fatal) brain disease (usually in middle age)
         caused by an unidentified slow virus; characterized by
         progressive dementia and gradual loss of muscle control
         [syn: Creutzfeldt-Jakob disease, CJD, Jakob-
         Creutzfeldt disease]