autoimmune Syllabification: (au·to·im·mune)Pronunciation: /ˌôtōəˈmyo͞on/Translate autoimmune | into Italian Definition of autoimmune adjective Medicine of or relating to disease caused by antibodies or lymphocytes produced against substances naturally present in the body:the infection triggers an autoimmune responseDerivatives autoimmunityPronunciation: /-nitē/ noun autoimmune in other Oxford dictionaries Definition of autoimmune in the British & World English dictionary