Source : Free On-Line Dictionary of Computing

Saturday-night special
     
        (From police slang for a cheap handgun) A {quick-and-dirty}
        program or feature {kluge}d together during off hours, under a
        deadline, and in response to pressure from a {salescritter}.
        Such hacks are dangerously unreliable, but all too often sneak
        into a production release after insufficient review.
     
        [{Jargon File}]
     
        (1994-11-11)