Aggrieved parties getting hold of a scrounger (8)
I believe the answer is:
parasite
'scrounger' is the definition.
(thesaurus)
'aggrieved parties getting hold of a' is the wordplay.
'aggrieved' indicates an anagram (I've seen this in other clues).
'getting hold of' means one lot of letters goes inside another.
'parties' is an anagram of 'parsite'.
'parsite' enclosing 'a' is 'PARASITE'.
(Other definitions for parasite that I've seen before include "sponge" , "Creature that lives off others" , "One living off another" , "Twenty five dn [LEECH]" , "Animal or plant that lives off another" .)