Help with a heist (4)
I believe the answer is:
abet
'help with a heist' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for abet that I've seen before include "Give aid to" , "Aid - connive with" , "Criminally endorse" , "Assist in some nefarious activity" , "Assist (a criminal)" .)