ectozoon

[ ek-tuh-zoh-on, -uh n ]
/ ˌɛk təˈzoʊ ɒn, -ən /

noun, plural ec·to·zo·a [ek-tuh-zoh-uh] /ˌɛk təˈzoʊ ə/. Biology.

any animal parasite, as the louse, that lives on the surface of its host (opposed to entozoon).
Also ectozoan.

Origin of ectozoon

First recorded in 1855–60; ecto- + -zoon

Medical definitions for ectozoon

ectozoon
[ ĕk′tə-zōŏn′ ]

n. pl. ec•to•zo•a (-zōə)

An animal parasite, such as a flea or louse, living on the exterior of the host organism.