Olsz·tyn (ôl?sht?n) A city of northern Poland southeast of Gda?sk. Founded by the Teutonic Knights in 1348, it was ceded to Poland in 1466 and to Prussia in 1772. It reverted to Poland in 1945.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.Olsztyn (Polish ??l?tin) n (Placename) a town in NE Poland: founded in 1334 by the Teutonic Knights; communications centre. Pop: 176 000 (2005 est)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Ol?sztyn (??l ?t?n) n. a city in NE Poland. 739,000. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.