Actors' one take shows discipline (9)
I believe the answer is:
castigate
'discipline' is the definition.
(thesaurus)
'actors' one take' is the wordplay.
'actors'' becomes 'cast' (group of actors).
'one' becomes 'i' (Roman numeral).
'take' becomes 'gate' (I've seen this in another clue).
'cast'+'i'+'gate'='CASTIGATE'
'shows' acts as a link.
(Other definitions for castigate that I've seen before include "Berate" , "Take a piece out of" , "Severely reprimand" , "Slap down" , "Censure severely" .)