Bum a fag end? (4)
I believe the answer is:
butt
I believe this clue is a triple definition!
'bum' is the first definition.
('butt' can be a synonym of 'bum')
'a fag' is the second definition.
(thesaurus)
'end?' is the third definition.
(thesaurus)
(Other definitions for butt that I've seen before include "Cigarette end" , "Contralto" , "Hit with the head; object of ridicule" , "Object of scorn, of humour" , "ram > end" .)