Film director breaking into a frenzied bombast (9)
I believe the answer is:
tarantino
'film director' is the definition.
(I've seen this before)
'breaking into a frenzied bombast' is the wordplay.
'breaking' means one lot of letters goes inside another.
'frenzied' indicates an anagram.
'bombast' becomes 'rant' (synonyms).
'into'+'a'='intoa'
'intoa' with letters rearranged gives 'taino'.
'taino' going around 'rant' is 'TARANTINO'.
(Other definitions for tarantino that I've seen before include "He makes films" , "Quentin ... film maker" , "Quentin -, American film director" , "Quentin -, US director" , "Who in tarnation is this US film-maker?" .)