DuckCorp Dico

Found one definition

1.                 From The Jargon File (version 4.4.7, 29 Dec 2003):
                   
   
   
                   
                     
   SED
    /S·E·D/, n.
       [TMRC, from ‘Light-Emitting Diode’] Smoke-emitting diode. A friode that
       lost the war. See also LER. [Not to be confused with sed(1), the Unix
       stream editor. —ESR]