Help a criminal in Austria? Better not! (4)
I believe the answer is:
abet
'help a criminal' is the definition.
(I've seen this before)
'in austria? better not' is the wordplay.
'in' indicates a hidden word.
'ABET' is hidden within 'austria better not'.
(Other definitions for abet that I've seen before include "Aid (in wrongdoing)" , "Aid - connive with" , "support wrongdoing" , "Assist (a criminal)" , "Help in wrongdoing" .)