Disheartened revolutionary's dance? (4)
I believe the answer is:
reel
'dance?' is the definition.
(I know that reel is a type of square dance)
'disheartened revolutionary's' is the wordplay.
'disheartened' means to remove the middle letters.
'revolutionary' becomes 'rebel' (rebel is a kind of revolutionary).
'rebel' with its middle removed is 'REEL'.
(Other definitions for reel that I've seen before include "Folk dance" , "Stagger with rod winder" , "Part of a film; stagger" , "long stretch of film" , "Dance - sway - cotton holder" .)