pneumocystis Syllabification: (pneu·mo·cys·tis)Pronunciation: /ˈn(y)o͞omōˌsistis/Definition of pneumocystis noun Medicine a parasitic protozoan that can cause fatal pneumonia in people affected with immunodeficiency disease. Pneumocystis carinii, phylum Sporozoa pneumocystis in other Oxford dictionaries Definition of pneumocystis in the British & World English dictionary
