Wiktionary
bootable
a. (context computing of a disk, etc. English) That can be booted; from which one can boot the system. n. (context computing English) A disk or other medium from which the system can be booted.
Usage examples of "bootable".
Your computer notices a bootable disk in the floppy or CD-ROM drive, loads in some object code from that disk, and blindly begins to execute it.