pathological Syllabification: (path·o·log·i·cal)Pronunciation: /ˌpaTHəˈläjikəl/ (also pathologic)Translate pathological | into French | into German | into Italian | into Spanish Definition of pathological adjective of or relating to pathology:the interpretation of pathological studies involving, caused by, or of the nature of a physical or mental disease:pathological changes associated with senile dementia informal compulsive; obsessive:a pathological gamblerDerivatives pathologically adverb pathological in other Oxford dictionaries Definition of pathological in the British & World English dictionary