Help in wrongdoing (4)
I believe the answer is:
abet
'help in wrongdoing' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for abet that I've seen before include "Assist illegally" , "Criminally endorse" , "Support, aid" , "Assist in some nefarious activity" , "Aid and help, perhaps in crime" .)