Heartless Tory stifles anger over daughter's misfortune (7)
I believe the answer is:
tragedy
'misfortune' is the definition.
(tragedy is a kind of misfortune)
'heartless tory stifles anger over daughter's' is the wordplay.
'heartless' says to hollow out the word (remove centre letters).
'stifles' means one lot of letters goes inside another.
'anger' becomes 'rage' (rage is a kind of anger**).
'over' is a charade indicator (letters next to each other).
'daughter' becomes 'd'.
'tory' with its centre taken out is 'ty'.
'rage'+'d'='raged'
'ty' enclosing 'raged' is 'TRAGEDY'.
(Other definitions for tragedy that I've seen before include "Calamitous happening, great misfortune" , "Play with a gloomy finish" , "Catastrophic event that causes great sadness" , "Gyrated (anag)" , "Sad story" .)