Modern Greekn. Greek since the early 1500s. Also called New Greek.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.Modern Greek n (Languages) the Greek language since about 1453 ad (the fall of Byzantium). Compare Demotic, Katharevusa Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Mod?ern Greek? n. the Greek language since c1500. Abbr.: ModGk Also called New Greek. [1740?50] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.