entozoon

noun, plural en·to·zo·a [en-tuh–zoh–uh] /ˌɛn təˈzoʊ ə/.

1. any animal parasite, as an intestinal worm, that lives within the body of its host (opposed to ectozoon).

noun plural -zoa (-ˈzəʊə)

1. any animal, such as a tapeworm, that lives within another animal, usually as a parasite

n. pl. en•to•zo•a (-zō′ə)

1. An animal parasite, such as a tapeworm or liver fluke, inhabiting any of the internal organs or tissues.