Hit, say, to cover (4)
I believe the answer is:
wrap
'cover' is the definition.
(wrapping is a kind of covering)
'hit say' is the wordplay.
'hit' becomes 'rap' (I've seen this in other clues).
'say' shows a homophone (sound like).
'rap' is a homophone of 'WRAP'.
'to' is the link.
(Other definitions for wrap that I've seen before include "Cover; loose garment" , "End of a filming session" , "Fold covering around something" , "Enclose completely" , "Protectively cover" .)