coccidiosisPronunciation: /kɒkˌsɪdɪˈəʊsɪs/Definition of coccidiosis noun [mass noun] a disease of birds and mammals that chiefly affects the intestines, caused by coccidia. Origin: late 19th century: from coccidium (singular of modern Latin Coccidia; see coccidia) + -osiscoccidiosis in other Oxford dictionaries Definition of coccidiosis in the US English dictionary