zymo- or zym-pref.1. Fermentation: zymurgy.2. Enzyme: zymogram.[New Latin z?mo-, from Greek z?m?, leaven.]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.zymo- or before a vowel zym-combining formindicating fermentation: zymology. [from Greek zum? leaven]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014zymo- a combining form meaning ?ferment,? ?leaven?: zymogen. Also, esp. before a vowel,zym-. [comb. form representing Greek zym? leaven] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.