Use empty platitude in speech (9)
I believe the answer is:
operation
'use' is the definition.
(thesaurus)
'empty platitude in speech' is the wordplay.
'empty' suggests removing the centre.
'in' is an insertion indicator.
'speech' becomes 'oration' (oration is a kind of speech).
'platitude' with its centre removed is 'pe'.
'pe' put inside 'oration' is 'OPERATION'.
(Other definitions for operation that I've seen before include "medical treatment" , "Manoeuvre - military action" , "Act of surgery" , "Surgical or military piece of work" , "financial transaction" .)