Use a shroud, by the sound of it (5)
I believe the answer is:
avail
'use' is the definition.
(availing is a kind of using)
'a shroud by the sound of it' is the wordplay.
'shroud' becomes 'veil' (I've seen this in another clue).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'veil' sounds like 'vail'.
'a'+'vail'='AVAIL'
(Other definitions for avail that I've seen before include "Help, benefit" , "Medal (informal)" , "See 3" , "(Of no) use or benefit" , "Be of help or advantage" .)