Burning hole in painting, say (6)
I believe the answer is:
ardent
'burning' is the definition.
(both can mean passionate)
'hole in painting say' is the wordplay.
'hole' becomes 'den' (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'painting say' becomes 'art' (painting is a kind of art).
'den' placed within 'art' is 'ARDENT'.
(Other definitions for ardent that I've seen before include "Fiery and zealous" , "Ranted, being passionate" , "passion" , "Zealous - ranted (anag)" , "Hot" .)