Confidential assistant among raiders (4)
I believe the answer is:
aide
'confidential assistant' is the definition.
(I've seen this before)
'among raiders' is the wordplay.
'among' says the answer is hidden in the clue.
'AIDE' can be found hidden inside 'raiders'.
(Other definitions for aide that I've seen before include "Personal assistant in the military" , "Confidential assistant or advisor" , "Political assistant" , "Military officer acting as assistant" , "Somebody helping" .)