Il·lyr·i·a (?-lîr??-?) also Il·lyr·i·cum (-?-k?m) An ancient region of the Balkan Peninsula on the Adriatic coast. Occupied in prehistoric times by an Indo-European-speaking people, the area became the Roman province of Illyricum after the final conquest of the Illyrians in 35-33 bc. The name was revived by Napoleon for the provinces of Illyria (1809-1815) and retained for the kingdom of Illyria, a division of Austria from 1816 to 1849.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.Illyria (??l??r??) n (Placename) an ancient region of uncertain boundaries on the E shore of the Adriatic Sea, including parts of present-day Croatia, Montenegro, and AlbaniaCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Il?lyr?i?a (??l??r i ?) n. an ancient country along the E coast of the Adriatic. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.