load·er (l??d?r)n. A computer program that transfers data from offline memory into internal storage.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.loader (?l??d?) n1. (Professions) a person who loads a gun or other firearm2. (Firearms, Gunnery, Ordnance & Artillery) a person who loads a gun or other firearm3. (Firearms, Gunnery, Ordnance & Artillery) (in combination) designating a firearm or machine loaded in a particular way: breech-loader; top-loader. 4. (Computer Science) computing a system program that takes a program in a form close to machine code and places it into a memory for executionCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014