Source : Free On-Line Dictionary of Computing

hosed
     
         A somewhat humorous variant of "{down}", used
        primarily by {Unix} {hackers}.  "Hosed" implies a condition
        thought to be relatively easy to reverse.  It is also widely
        used of people in the mainstream sense of "in an extremely
        unfortunate situation".  The term was popularised by fighter
        pilots refering to being hosed by machine gun fire (date?).
        Usage in hackerdom dates back to {CMU} in the 1970s or
        earlier.
     
        {"Acronyms and Abbreviations" from UCC, Ireland
        (http://www.ucc.ie/cgi-bin/acronym)} expands it as "Hardware
        Or Software Error Detected", though this is probably a
        back-formation.
     
        The {Jargon File} version 4.1.4 1999-06-17 says that it was
        probably derived from the Canadian slang "hoser" (meaning "a
        man, esp. one who works at a job that uses physical rather
        than mental skills and whose habits are slightly offensive but
        amusing").
     
        One correspondant speculates about an allusion to a hose-like
        body part.
     
        Once upon a time, a {Cray} that had been experiencing periodic
        difficulties crashed, and it was announced to have been hosed.
        It was discovered that the crash was due to the disconnection
        of some coolant hoses.  The problem was corrected, and users
        were then assured that everything was OK because the system
        had been rehosed.  See also {dehose}.
     
        See also: {hose}.
     
        (1999-10-28)