WordNet (r) 3.0 (2006):

subacute sclerosing panencephalitis
    n 1: a rare chronic progressive encephalitis caused by the
         measles virus and occurring primarily in children and young
         adults; death usually occurs within three years;
         characterized by primary measles infection before the age
         of two years [syn: subacute sclerosing panencephalitis,
         SSPE, inclusion body encephalitis, subacute inclusion
         body encephalitis, sclerosing leukoencephalitis,
         subacute sclerosing leukoencephalitis, Bosin's disease,
         Dawson's encephalitis, Van Bogaert encephalitis]