Allow penalty (8)
I believe the answer is:
sanction
This clue is a double definition.
'allow' is the first definition.
(thesaurus)
'penalty' is the second definition.
(thesaurus)
(Other definitions for sanction that I've seen before include "Agree to - penalty" , "Permission or approval as for course of action" , "Give final permission" , "Official approval (for an action)" , "Allow; punish" .)