Merriam-Webster Collegiate Dictionary - plasmodium

 noun  (plural plasmodia)  Etymology: New Latin, from plasm- + -odium thing resembling, from Greek -odes like  Date: 1875  1.  a. a motile multinucleate mass of protoplasm resulting from fusion of uninucleate amoeboid cells; also an organism (as a stage of a slime mold) that consists of such a structure  b. syncytium 1  2. a sporozoan parasite (genus Plasmodium) that is the causative agent of malaria