New South Wales A state of southeast Australia on the Tasman Sea. Settled in 1788 as a British penal colony, it is Australia’s oldest state. Sydney is the capital and largest city.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.New South Wales n (Placename) a state of SE Australia: originally contained over half the continent, but was reduced by the formation of other states (1825?1911); consists of a narrow coastal plain, separated from extensive inland plains by the Great Dividing Range; the most populous state; mineral resources. Capital: Sydney. Pop: 7 272 800 (2012). Area: 801 428 sq km (309 433 sq miles) Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014New? South` Wales? n. a state in SE Australia. 6,115,000; 309,433 sq. mi. (801,430 sq. km). Cap.: Sydney. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.