Noun | 1. endozoan - any of various parasites that live in the internal organs of animals (especially intestinal worms)endoparasite, entoparasite, entozoan, entozoonparasite - an animal or plant that lives in or on a host (another animal or plant); it obtains nourishment from the host without benefiting or killing the host | Adj. | 1.endozoan - of or relating to entozoaentozoan |