Tir·yns (tîr??nz, t??r?nz) An ancient city of southern Greece in the eastern Peloponnesus. It contains extensive ruins of a pre-Homeric citadel.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.Tir?yns (?t?r ?nz) n. an ancient city in Greece, in Peloponnesus. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.