Source : WordNet®

virtual reality
     n : a hypothetical three-dimensional visual world created by a
         computer; user wears special goggles and fiber optic
         gloves etc., and can enter and move about in this world
         and interact with objects as if inside it

Source : Free On-Line Dictionary of Computing

virtual reality
     
        (VR)
     
        1.  Computer simulations that use 3D graphics and
        devices such as the {data glove} to allow the user to interact
        with the simulation.
     
        2.  A form of network interaction incorporating aspects
        of role-playing games, interactive theater, improvisational
        comedy, and "true confessions" magazines.  In a virtual
        reality forum (such as {Usenet}'s {news:alt.callahans}
        newsgroup or the {MUD} experiments on {Internet} and
        elsewhere), interaction between the participants is written
        like a shared novel complete with scenery, "foreground
        characters" that may be personae utterly unlike the people who
        write them, and common "background characters" manipulable by
        all parties.  The one iron law is that you may not write
        irreversible changes to a character without the consent of the
        person who "owns" it, otherwise, anything goes.
     
        See {bamf}, {cyberspace}.
     
        [{Jargon File}]
     
        (1995-01-30)