Not all stifled emotions, making protest (4)
I believe the answer is:
demo
'protest' is the definition.
(I've seen this before)
'not all stifled emotions making' is the wordplay.
'not all' says the answer is hidden in the clue.
'DEMO' is hidden within 'stifled emotions making'.
(Other definitions for demo that I've seen before include "Eg, protest march" , "In brief, a public event as of protest under dome" , "March (abbr)" , "Protest (abbr)" , "Protest march (sl.)" .)