I.
See main entry: ↑ defragment
II. de ‧ frag ‧ ment /ˌdiːfræɡˈment $ diːˈfræɡment, ˌdiːfræɡˈment/ BrE AmE ( also de‧frag /diːˈfræɡ/ informal ) verb [transitive]
to change the way in which the ↑ file s 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]