Coincide concerning circuit (7)
I believe the answer is:
overlap
'coincide' is the definition.
(I know this)
'concerning circuit' is the wordplay.
'concerning' becomes 'over' (both can mean relating to).
'circuit' becomes 'lap' (synonyms).
'over'+'lap'='OVERLAP'
(Other definitions for overlap that I've seen before include "common ground" , "Put extra cover on" , "Common area of interest" , "Project" , "Coincide in part" .)