Animal; independently moving organic unit: spermatozoon.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
n combining form
(Biology) indicating an individual animal or an independently moving entity derived from an animal: spermatozoon.
[from Greek zōion animal]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
a combining form meaning “animal,” “organism” of the kind specified by the initial element, often corresponding to zoological taxa ending in -zoa, with -zoon used to name a single member of such a class: protozoon.
[< New Latin zōon < Greek zôion animal]
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