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Webster 1913 Edition
Epizoon
‖
Epˊi-zo′ön
,Noun.
pl. 
Epizoa 
(#)
. [NL., fr. Gr. 
ἐπί 
upon + ζῶ,ον 
animal.] (Zoöl.) 
One of the artificial group of invertebrates of various kinds, which live parasitically upon the exterior of other animals; an ectozoön. Among them are the lice, ticks, many acari, the lerneans, or fish lice, and other crustaceans.