Blunt, to no avail (9)
I believe the answer is:
pointless
I believe this clue is a double definition.
'blunt' is the first definition.
(similar in meaning)
'no avail' is the second definition.
(I've seen this before)
'to' acts as a link.
(Other definitions for pointless that I've seen before include "having scored zero" , "Quite vain" , "Single-track railway might be so" , "Having little use" , "silly" .)