Bagh·dad or Bag·dad (b?g?d?d?) The capital and largest city of Iraq, in the center of the country on the Tigris River. Founded in the eighth century, it was heavily damaged by US forces during the Gulf War and the Iraq War.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.Baghdad (bæ??dæd) or Bagdadn (Placename) the capital of Iraq, on the River Tigris: capital of the Abbasid Caliphate (762?1258). Pop: 5 910 000 (2005 est)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Bagh?dad or Bag?dad (?bæg dæd, b?g?dæd) n. the capital of Iraq, in the central part, on the Tigris. 4,648,609. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.