de·plet·ed (d?-pl??t?d)adj.1. Extremely tired; exhausted or worn out.2. Relating to or being uranium whose fissionable isotope uranium 235 has been mostly removed, consisting primarily of the remaining isotope uranium 238.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.depleted (d??pli?t?d) adjreduced or exhaustedCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014