Meaning: Able to withstand attack. Synonyms: unassailable; unattackable; impregnable; inviolable; secure; strong. Context examples: an impregnable fortress / fortifications that made the frontier inviolable. Similar: invulnerable (immune to attack; impregnable)
Definition - What does Magnetic Disk mean? A magnetic disk is a storage device that uses a magnetization process to write, rewrite and access data. It is covered with a magnetic coating and stores data in the form of tracks, spots and sectors. Hard disks, zip disks and floppy disks are common examples of magnetic disks.
Magnetic disks are platters coated with iron oxide, like tape and drums. An arm with a tiny wire coil, the read/write (R/W) head, moves radially over the disk, which is divided into concentric tracks composed of small arcs, or sectors, of data.