Star in spot orating terribly (11)
I believe the answer is:
protagonist
'star' is the definition.
(thesaurus)
'spot orating terribly' is the wordplay.
'terribly' is an anagram indicator.
'spot'+'orating'='spotorating'
'spotorating' is an anagram of 'PROTAGONIST'.
'in' acts as a link.
(Other definitions for protagonist that I've seen before include "champion" , "Leading character in a play, novel, etc" , "Advocate" , "Key character in a novel" , "Hero" .)