depleted uranium n (Chemistry) chem uranium containing a smaller proportion of the isotope uranium?235 than is present in the natural form of uranium; used in anti-tank weapons and other armaments Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014