Couple into white magic (4)
I believe the answer is:
item
'couple' is the definition.
(a romantic couple are 'an item')
'into white magic' is the wordplay.
'into' indicates a hidden word.
'ITEM' is hidden within 'white magic'.
(Other definitions for item that I've seen before include "story" , "Two people widely seen as one?" , "Also no more" , "A single piece of information" , "Piece in paper" .)