ketonuria Syllabification: (ke·to·nu·ri·a)Pronunciation: /ˌkētōˈn(y)o͝orēə/Definition of ketonuria noun Medicine the excretion of abnormally large amounts of ketone bodies in the urine, characteristic of diabetes mellitus, starvation, or other medical conditions. ketonuria in other Oxford dictionaries Definition of ketonuria in the British & World English dictionary