Look, fellows, current's coming in! (4)
I believe the answer is:
mien
'look' is the definition.
(mien means a look or impression)
'fellows current's coming in' is the wordplay.
'fellows' becomes 'men' (fellow can mean a man).
'current' becomes 'I' (symbol for electric current).
'coming in' is an insertion indicator.
'men' going around 'i' is 'MIEN'.
(Other definitions for mien that I've seen before include "Bearing, demeanour" , "A manner like mine" , "Appearance is strangely mine" , "Dignified manner" , "Comportment" .)