To be of use as part of a bridal outfit, by the sound of it (5)
I believe the answer is:
avail
'to be of use' is the definition.
(I've seen this in another clue)
'as part of a bridal outfit by the sound of it' is the wordplay.
'as' becomes 'a' (I can't explain this - if you can you should believe this answer much more).
'part of a bridal outfit' becomes 'veil' (I've seen this in another clue).
'by the sound of it' shows a homophone (sound like).
'veil' is a homophone of 'vail'.
'a'+'vail'='AVAIL'
Can you help me to learn more?
(Other definitions for avail that I've seen before include "Provide help; profit" , "Help, benefit" , "Be of service to" , "Use to one's advantage" , "(Of no) use or benefit" .)