Bones in bag used by artist (5)
I believe the answer is:
sacra
'bones' is the definition.
(I've seen this before)
'bag used by artist' is the wordplay.
'bag' becomes 'sac' (I've seen this before).
'used by' is a charade indicator (letters next to each other).
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'sac'+'ra'='SACRA'
'in' acts as a link.
(Other definitions for sacra that I've seen before include "Bones that form the human pelvic arch" , "Triangular bones" .)