Stick to prohibition outside (5)
I believe the answer is:
baton
'stick' is the definition.
(term for a stick or staff)
'to prohibition outside' is the wordplay.
'prohibition' becomes 'ban' (ban is a kind of prohibition).
'outside' is an insertion indicator (some letters go outside others).
'to' put into '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" .)