sarcoidosis Syllabification: (sar·coid·o·sis)Pronunciation: /ˌsärˌkoiˈdōsis/Definition of sarcoidosis noun a chronic disease of unknown cause characterized by the enlargement of lymph nodes in many parts of the body and the widespread appearance of granulomas derived from the reticuloendothelial system. sarcoidosis in other Oxford dictionaries Definition of sarcoidosis in the British & World English dictionary