Source : Free On-Line Dictionary of Computing

Multi-User Shared Hallucination
     
         (MUSH) A user-extendable {MUD}.
        A MUSH provides commands which the players can use to
        construct new rooms or make objects and puzzles for other
        players to explore.
     
        {(http://www.cis.upenn.edu/~lwl/muds.html)}.
     
        (1995-03-16)