Irish Republican Army n (Government, Politics & Diplomacy) a militant organization of Irish nationalists founded with the aim of striving for a united independent Ireland by means of guerrilla warfare. Abbreviation: IRA Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014I?rish Repub?lican Ar?my n. an underground Irish nationalist organization founded to work for Irish independence from England: its Provisional wing, until the 1999 peace agreement, followed a policy of terrorism. Abbr.: IRA, I.R.A. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.