Source : Free On-Line Dictionary of Computing

foobar
     
         Another common {metasyntactic variable}; see {foo}.
        Hackers do *not* generally use this to mean {FUBAR} in either
        the slang or jargon sense.
     
        According to a german correspondent, the term was coined
        during WW2 by allied troops who could not pronounce the german
        word "furchtbar" (horrible, terrible, awful).
     
        [{Jargon File}]
     
        (2003-07-03)