Rubbish ravenously eaten — I approve (12)
I believe the answer is:
gobbledegook
'rubbish' is the definition.
(thesaurus)
'ravenously eaten i approve' is the wordplay.
'ravenously eaten' becomes 'gobbled'.
'i' becomes 'ego' (I've seen this in other clues).
'approve' becomes 'ok' (synonyms).
'gobbled'+'ego'+'ok'='GOBBLEDEGOOK'
(Other definitions for gobbledegook that I've seen before include "mumbo-jumbo" , "Unreadable jargon" , "pompous jargon" , "Load of tripe" , "Unintelligible jargon" .)