'Epizoic' definitions:

Definition of 'epizoic'

(from WordNet)
adjective
Living or growing on the exterior surface of an animal usually as a parasite; "an epizoic plant parasite" [ant: endozoic, entozoan, entozoic]

Definition of 'Epizoic'

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