Odd newsman raised objection (5)
I believe the answer is:
demur
'objection' is the definition.
(demur is a kind of objection)
'odd newsman raised' is the wordplay.
'odd' becomes 'rum' (I've seen this before).
'newsman' becomes 'ed'.
'raised' says the letters should be written in reverse.
'rum'+'ed'='rumed'
'rumed' written backwards gives 'DEMUR'.
(Other definitions for demur that I've seen before include "'Object, show reluctance (5)'" , "Raise mild objection" , "Protest mildly, object" , "Waver" , "Raise objections" .)