Adviser from Maidenhead (4)
I believe the answer is:
aide
'adviser' is the definition.
'from maidenhead' is the wordplay.
'from' indicates the answer is hidden within the clue.
'AIDE' can be found hidden inside 'maidenhead'.
(Other definitions for aide that I've seen before include "One to assist" , "Somebody helping" , "Right-hand man/woman" , "Assistant to a more senior person" , "Personal assistant in the military" .)