/ Dictionary / Index E ectozoon: Meaning and Definition of Find definitions for: ec•to•zo•on Pronunciation: (ek"tu-zō'on, -un), [key] — pl. -zo•a any animal parasite, as the louse, that lives on the surface of its host (opposed to entozoon). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: ectozoon (Thesaurus) ectozoic Ectrin Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language