Futile, pointless (4)
I believe the answer is:
vain
I believe this clue is a double definition.
'futile' is the first definition.
(synonyms)
'pointless' is the second definition.
(I've seen this in another clue)
(Other definitions for vain that I've seen before include "without success" , "Conceited - or a waste of time" , "Conceited or unsuccessful" , "Swollen-headed" , "Having an exaggerated sense of self-importance" .)