Old lady, cruel at heart and dead rough (9)
I believe the answer is:
granulate
'rough' is the definition.
(thesaurus)
'old lady cruel at heart and dead' is the wordplay.
'old lady' becomes 'gran' (short for grandmother).
'cruel at heart' becomes 'u' (I can't justify this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'dead' becomes 'late' (similar in meaning).
'gran'+'u'+'late'='GRANULATE'
Can you help me to learn more?
(Other definitions for granulate that I've seen before include "Break down into small fragments" , "Break into fine particles" .)