A trophozoite (G. trope, nourishment + zoon, animal) is the activated, feeding stage in the life cycle of certain protozoan parasites such as in the malaria-causing Plasmodium falciparum and those of the Giardia group. (The opposite of the trophozoite state is the thick-walled cyst form
Greek: (τροφος trophos ‚nutrition‘ und ζοον Zoon ‚animal‘) is the vegetative phase of adult protists, meaning the phase where the protozoa are metabolically active in their natural environment and do not replicate.