yum (y?m)interj.1. Used to express appreciation of or eagerness for a tasty food or beverage.2. Used to express appreciation for something attractive or to express eagerness for a pleasurable experience.[Imitative.]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.yum (j?m) interj a variant of yummyCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014yum-yum (?y?m?y?m) also yum interj. (used to express enjoyment or satisfaction, esp. in the taste of food.) [1880?85] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.