encephalopathy Syllabification: (en·ceph·a·lop·a·thy)Pronunciation: /enˌsefəˈläpəTHē/Definition of encephalopathy noun (plural encephalopathies) Medicine a disease in which the functioning of the brain is affected by some agent or condition (such as viral infection or toxins in the blood). encephalopathy in other Oxford dictionaries Definition of encephalopathy in the British & World English dictionary