ディスマウント

noun, noun or participle which takes 'suru', transitive verb

dismounting (a disk); unmounting

Computing term for logically detaching a storage volume or disk image so it is no longer accessible by the file system. Used as a noun or with する as a transitive verb.

• USBメモリをディスマウントしてから抜ぬいてください。

  Please dismount the USB flash drive before removing it.