Raise up pretty velvet covers (4)
I believe the answer is:
levy
'raise' is the definition.
(synonyms)
'up pretty velvet covers' is the wordplay.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'covers' says the answer is hidden in the clue (I've seen 'covering' mean this).
'yvel' is hidden in the letters of 'pretty velvet'.
'yvel' backwards is 'LEVY'.
(Other definitions for levy that I've seen before include "enlisted troops" , "Financial charge" , "Imposition of charge" , "tax money" , "Impose and collect (money)" .)