New World North America, Central America, and South America; the Americas. The term was first used by the Italian historian Peter Martyr (1457-1526), whose De Rebus Oceanicis et Novo Orbe (1516) chronicled the discovery of America.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 World n (Placename) the New World the Americas; the western hemisphere Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014West?ern Hem?isphere n. 1. the part of the globe west of the Atlantic, including North and South America, their islands, and the surrounding waters. 2. that half of the earth traversed in passing westward from the prime meridian to 180° longitude. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.