Secretly, wannabe tries to assist in wrongdoing (4)
I believe the answer is:
abet
'assist in wrongdoing' is the definition.
(I've seen this in another clue)
'secretly wannabe tries to' is the wordplay.
'secretly' indicates a hidden word.
'ABET' is hidden in the letters of 'wannabe tries to'.
(Other definitions for abet that I've seen before include "Aid (in wrongdoing)" , "Assist wrongly!" , "Beat up by way of help" , "Assist in some nefarious activity" , "Assist (in wrongdoing)" .)