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defrag

[dee-frag]
verb (used with object), de·fragged, de·frag·ging. Computers, Informal.
  1. defragment.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for defrag

defrag

verb -frags, -fragging or -fragged
  1. to consolidate fragmented files and folders on (the hard drive of a computer or other electronic device) in order to make it run more efficiently

Word Origin for defrag

short for defragment
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012