From Longman Dictionary of Contemporary Englishdefragmentde‧frag‧ment /ˌdiːfræɡˈment $ diːˈfræɡment, ˌdiːfræɡˈment/ (also defrag /diːˈfræɡ/ informal) verb [transitive] to change the way in which the files on a computer’s hard drive are stored and organized, by putting related information together so that the computer works more effectively It should start working faster after we defrag your disk. —defrag /ˈdiːfræɡ/ noun [countable]→ See Verb table
