What is "epizoic"

Epizoic \Ep`i*zo"ic\, a. (Zo["o]l.) Living upon the exterior of another animal; ectozoic; -- said of external parasites. [1913 Webster] ||

"living on the surface or in the skin of animals," 1832, from epizoon + -ic.

a. living or growing on the external surface of an animal (not always as a parasite)

adj. living or growing on the exterior surface of an animal usually as a parasite; "an epizoic plant parasite" [ant: entozoic]