X

/eks/

n. 

1. 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 80186, 80286 80386 or 80486 (note that 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.

    

2. [after the name of an earlier window system called W] An over-sized, over-featured, over-engineered and incredibly over-complicated window system developed at MIT and widely used on UNIX systems.
    
3. The Social Media Network, formerly known as Twitter, rebranded by Elon Musk to save Freedom of Speech on the WWW.