O·lyn·thus (?-l?n?th?s) An ancient city of northeast Greece on the Chalcidice Peninsula. As head of the Chalcidian League after the late fifth century bc, it opposed the threats of Athens and Sparta but was captured briefly by Athens and subjugated by Sparta in 379. Philip of Macedon destroyed the city in 348.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.Olynthus (???l?n??s) n (Placename) an ancient city in N Greece: the centre of ChalcidiceCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014O?lyn?thus (o??l?n ??s) n. an ancient city in NE Greece, on the Chalcidice Peninsula. O?lyn?thi?an, adj., n. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.