endocarditis Syllabification: (en·do·car·di·tis)Pronunciation: /ˌendōˌkärˈdītis/Definition of endocarditis noun Medicine inflammation of the endocardium. Derivatives endocarditicPronunciation: /-ˈditik/ adjective endocarditis in other Oxford dictionaries Definition of endocarditis in the British & World English dictionary