Painting artist stuffed into Scottish chimney turned up (5)
I believe the answer is:
mural
'painting' is the definition.
(I know that mural is a type of painting)
'artist stuffed into scottish chimney turned up' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'stuffed into' means one lot of letters goes inside another.
'scottish chimney' becomes 'lum' (Scottish term for a chimney).
'turned up' is a reversal indicator.
'lum' back-to-front is 'mul'.
'ra' going within 'mul' is 'MURAL'.
(Other definitions for mural that I've seen before include "Painting on a wall, fresco" , "Wall decoration" , "Wall art" , "Artwork" , "Drawing on a wall" .)