[noun] [C] - an animal or plant that lives on or in another animal or plant of a different type and feeds from itThe older drugs didn't deal effectively with the malaria parasite.(figurative) Financial speculators are parasites upon the national economy (= They are useless people supported by other people's work).
PARASITE
Meaning of PARASITE in English
Cambridge English vocab. Кембриджский английский словарь. 2012