Confident editor is secretly impressed? (6)
I believe the answer is:
dented
'impressed?' is the definition.
(I've seen this in another clue)
'confident editor is secretly' is the wordplay.
'is secretly' indicates the answer is hidden within the clue.
'DENTED' is hidden within 'confident editor'.
(Other definitions for dented that I've seen before include "Bashed in" , "Tended to be depresed" , "Made small depression in metal surface" , "made an impression" , "Dinged" .)