Act has pronounced polish, one may admit (9)
I believe the answer is:
turnstile
'polish one may admit' is the definition.
I can't tell whether this definition defines the answer.
'act has pronounced' is the wordplay.
'act' becomes 'turn' (theatre).
'has' means one lot of letters go next to another.
'pronounced' becomes 'stile' (I am not sure about this - if you are sure you should believe this answer much more).
'turn'+'stile'='TURNSTILE'
Can you help me to learn more?
(Other definitions for turnstile that I've seen before include "where spectators pass" , "Control for spectators' entry" , "Admission gate" , "Crowd-controlling gate, at entrance to sports-ground say" , "Means of regulating passage" .)