Source : WordNet®

DEd
     n : a doctor's degree in education [syn: {Doctor of Education},
         {EdD}]

Source : Free On-Line Dictionary of Computing

DED
     
        Dark-Emitting Diode (that is, a burned-out LED).  Compare
        {SED}, {LER}, {write-only memory}.  In the early 1970s both
        Signetics and Texas instruments released DED spec sheets as
        {AFJ}s (suggested uses included "as a power-off indicator").
     
        [{Jargon File}]