Curious journalist raised objection (5)
I believe the answer is:
demur
'objection' is the definition.
(demur is a kind of objection)
'curious journalist raised' is the wordplay.
'curious' becomes 'rum' ('rum' can be a synonym of 'curious').
'journalist' becomes 'ed' (short for editor).
'raised' says the letters should be written backwards.
'rum'+'ed'='rumed'
'rumed' back-to-front is 'DEMUR'.
(Other definitions for demur that I've seen before include "'Object, show reluctance (5)'" , "Dissent, object" , "Waver" , "Hesitate from uncertainty or object" , "Take exception (to)" .)