Electronic device starts iron working (10)
I believe the answer is:
transistor
'electronic device' is the definition.
(I've seen this before)
'starts iron working' is the wordplay.
'working' is an anagram indicator.
'starts'+'iron'='startsiron'
'startsiron' anagrammed gives 'TRANSISTOR'.
(Other definitions for transistor that I've seen before include "Electronic device" , "Electronic component" , "Radio" , "Semiconductor device" .)