1. [n]  electrical device used for etching by electrolytic means
2. [n]  an apparatus for the electrical transmission of pictures

ELECTROGRAPH is a 12 letter word that starts with E.

1. \E*lec"tro*graph\, n. [Electro- + -graph.]
   A mark, record, or tracing, made by the action of
   electricity.
   
   

2. \E*lec"tro*graph\, n. [Pref. electro + -graph.]
   1. An apparatus, controlled by electric devices, used to
      trace designs for etching.
   
   2. An instrument for the reproduction at a distance of
      pictures, maps, etc., by means of electricity.
   
   3. An image made by the R["o]ntgen rays; a sciagraph.
   
   4. A cinematograph using the arc light.