coc·cid·i·um 
(kŏk-sĭdē-əm)
(kŏk-sĭdē-əm)n. pl. coc·cid·i·a (-ē-ə)
Any of various parasitic apicomplexan protozoans that cause diseases such as toxoplasmosis in the digestive tract of vertebrates. Also called coccidian.
[New Latin Coccidium, former genus name : COCCUS + -idium, diminutive suff. (from Greek -idion).]