coccidium

from WordNet (r) 3.0 (2006)

coccidium
    n 1: parasitic on the digestive epithelium of vertebrates and
         higher invertebrates [syn: {coccidium}, {eimeria}]

from The Collaborative International Dictionary of English v.0.48

coccidium \coccidium\ n.; pl. {coccidia}. (Microbiol.)
   any sporozoan of the order {Coccidia}, parasitic on the
   digestive epithelium of vertebrates and higher invertebrates.
   It is the causative agent of coccidiosis, which can be a
   problem in poultry rearing.
   [WordNet 1.5 +PJC]