1. convention Used in various speech and writing contexts

(also in lowercase) in roughly its algebraic sense of "unknown

within a set defined by context" (compare N). Thus, the

abbreviation 680x0 stands for 68000, 68010, 68020, 68030 or

68040, and 80x86 stands for Intel 80186, Intel 80286,

Intel 80386 or Intel 80486. A Unix hacker might write

these as 680[0-4]0 and 80[1-4]86 or 680?0 and 80?86

respectively; see glob.