Roman official missing ridicule in song (4)
I believe the answer is:
tune
'song' is the definition.
(thesaurus)
'roman official missing ridicule' is the wordplay.
'roman official' becomes 'tribune' (I've seen this before).
'missing' suggests deleting specific letters.
'ridicule' becomes 'rib' ('rib' can be a synonym of 'ridicule').
'tribune' with 'rib' taken out is 'TUNE'.
'in' acts as a link.
(Other definitions for tune that I've seen before include "Air, melody" , "Of engine, adjust to run smoothly" , "Optimise the condition of" , "strain" , "Improve quality" .)