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.
The two most common secondary storage mediums are magnetic disk and magnetic tape. A magnetic disk can be a diskette or a hard disk. A diskette is usually 3-1/2 inches in diameter (in some rare cases older disks are 5-1/4 inches). A diskette is removable so you can take your data with you.