Stuttering with disapproval (3)
I believe the answer is:
tut
'disapproval' is the definition.
(I have seen 'Express disapproval' mean 'tut' so perhaps 'disapproval' could also mean 'tut')
'stuttering with' is the wordplay.
'with' indicates the answer is hidden within the clue.
'TUT' is hidden in the letters of 'stuttering'.
(Other definitions for tut that I've seen before include "Express impatience" , "Show disapproval" , "former ruler, in brief" , "Exclamation of disapproval or annoyance" , "Annoyed exclamation" .)