defragment
Concise Oxford English Dictionary © 2008 Oxford University Press:
defragment /ˌdiːfragˈmɛnt/
▶verb Computing reduce the fragmentation of (a file) by concatenating parts stored in separate locations.
– derivatives
defragmentation noun,
defragmenter noun.
defragmentation noun,
defragmenter noun.
'defragment' also found in these Oxford entries:

