Stick to prohibition outside (5)
I believe the answer is:
'stick' is the definition.
'to prohibition outside' is the wordplay.
'prohibition' becomes 'ban' (ban is a kind of prohibition).
'outside' means one lot of letters goes inside another.
'to' placed within 'ban' is 'BATON'.
(Other definitions for baton that I've seen before include "Conductor's wand" , "A stick for a conductor and policeman" , "Conductor's rod" , "Conductor wields it - or a policeman" , "weapon" .)