Omagh (???m??; ???m?) n1. (Placename) a market town in Northern Ireland. Pop: 19 910 (2001)2. (Placename) a district of W Northern Ireland, in Co Tyrone. Pop: 49 560 (2003 est). Area: 1130 sq km (436 sq miles)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014