Celebrity right to enter pastures new (9)
I believe the answer is:
superstar
'celebrity' is the definition.
(thesaurus)
'right to enter pastures new' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to enter' indicates putting letters inside.
'new' indicates anagramming the letters.
'pastures' anagrammed gives 'supestar'.
'r' put into 'supestar' is 'SUPERSTAR'.
(Other definitions for superstar that I've seen before include "Dazzling genius" , "Dazzling virtuoso" , "Extremely famous performer" , "Very famous person" , "Big name" .)