de·frag·ment

verb

/ˌdiːfræɡˈment/

/ˌdiːˈfræɡmənt/

(also informal defrag

/ˌdiːˈfræɡ/

)

(computing)

Verb Forms

present simple I / you / we / they defragment	/ˌdiːfræɡˈment/ /ˌdiːˈfræɡmənt/
he / she / it defragments	/ˌdiːfræɡˈments/ /ˌdiːˈfræɡmənts/
past simple defragmented	/ˌdiːfræɡˈmentɪd/ /ˌdiːˈfræɡməntɪd/
past participle defragmented	/ˌdiːfræɡˈmentɪd/ /ˌdiːˈfræɡməntɪd/
-ing form defragmenting	/ˌdiːfræɡˈmentɪŋ/ /ˌdiːˈfræɡməntɪŋ/

defragment something to organize where data is stored on a computer hard disk in the most efficient way, in order to reduce the time taken to access the data整理（计算机磁盘）碎片
Oxford Collocations Dictionary
Defragment is used with these nouns as the object:
drive