octal number system
- A numbering system whose base is 8, and whose utilized digits are 0--7. For example, decimal 10 is the same as octal 12, decimal 20 is octal 24, and decimal 26 is octal 32. Octal numbers usually have either a prefix or a suffix to identify them. For example, 032 has a letter O prefix to indicate that what follows is octal number 32. Also called octal system.