Make sound (6)
'make sound' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for heal that I've seen before include "Cure, make well" , "Cure, mend" , "Make better" , "Get healthy again" , "Become healthy again" .)
(Other definitions for repair that I've seen before include "Mend, put right" , "Restore after damage" , "service" , "Go - fix" , "do some darning" .)