D’Entrecasteaux Islands (French d??tr?kasto) pl n (Placename) a group of volcanic islands in the Pacific, off the SE coast of New Guinea: part of Papua New Guinea. Pop: 49 167 (1990 est). Area: 3141 sq km (1213 sq miles)Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014D’En?tre?cas?teaux Is?lands (?d?n tr??kæs to?, ?d?n-) n.pl. a group of islands in Papua New Guinea, off the E tip of New Guinea. Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.