Definition of "epizoic" [ep•i•zo•ic]

• Living or growing on the external surface of an animal. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Unionoidae shells provide a suitable substrate for epiphytic and epizoic colonization, and help stabilize fine-grained sediments that other organisms use for habitat."
• "Our epizoic literature is becoming so extensive that nobody is safe from its ad infinitum progeny."