Tough gran gets upset (8)
I believe the answer is:
gangster
'tough' is the definition.
(thesaurus)
'gran gets upset' is the wordplay.
'upset' indicates an anagram.
'gran'+'gets'='grangets'
'grangets' with letters rearranged gives 'GANGSTER'.
(Other definitions for gangster that I've seen before include "Member of criminal mob" , "Wise guy" , "One of a group of violent criminals" , "Villain" , "Crook" .)