Male attire ultimately could be answer! (8)
I believe the answer is:
menswear
'male attire' is the definition.
(I've seen this before)
'ultimately could be answer' is the wordplay.
'ultimately' becomes 'me' (I can't explain this - if you can you should give a lot more credence to this answer).
'could be' indicates an anagram.
'answer' with letters rearranged gives 'nswear'.
'me'+'nswear'='MENSWEAR'
(Other definitions for menswear that I've seen before include "Male attire" , "Male clothes" , "uniform, perhaps" , "Traditionally suits, shirts etc." , "Male clothing" .)