Preach, or otherwise censure (8)
I believe the answer is:
reproach
'censure' is the definition.
(thesaurus)
'preach or otherwise' is the wordplay.
'otherwise' is an anagram indicator.
'preach'+'or'='preachor'
'preachor' is an anagram of 'REPROACH'.
(Other definitions for reproach that I've seen before include "Reprove gently" , "Castigate" , "Express disapproval to (someone)" , "Rebuke or criticism" , "Scold(ing)" .)