e·chi·no·coc·cus 
(ĭ-kī′nə-kŏkəs)
(ĭ-kī′nə-kŏkəs)n. pl. e·chi·no·coc·ci (-kŏksī′, -kŏkī′)
Any of several parasitic tapeworms of the genus Echinococcus, the larvae of which infect mammals and form large, spherical cysts in the liver or lungs, causing serious or fatal disease.
[New Latin Echīnococcus, genus name : ECHINO- + -COCCUS.]