misprizer

mis·prize

 (mĭs-prīz′)
tr.v. mis·prized, mis·priz·ing, mis·priz·es
1. To despise.
2. To undervalue.

mis·priz′er n.
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.

misprizer

(mɪsˈpraɪzə)
n
a despiser or scorner
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014