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ectozoon

American  
[ek-tuh-zoh-on, -uhn] / ˌɛk təˈzoʊ ɒn, -ən /

noun

Biology.

plural

ectozoa
  1. any animal parasite, as the louse, that lives on the surface of its host (entozoon ).


Etymology

Origin of ectozoon

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