- V -   virtual -- A commonly used adjective that means having all of the properties of x while not necessarily being x. For example, "virtual Friday" in a workplace is the last day of work before a break, that is to say it is like Friday but may or may not actually be Friday. A "virtual reality" is an artificial environment that appears to be its own reality. On a mainframe, a "virtual machine" gives the user all of the properties and "feel" of a separate personal computer.   Virtual Reality Markup Language -- (abbreviation: VRML) A scripting language used to define three-dimensional "worlds".   virus -- An insidious piece of computer code written to damage systems. Viruses can be hidden in executable program files posted online.   VRML -- See Virtual Reality Markup Language.