Three-paneled artwork (8)
I believe the answer is:
triptych
'three-paneled artwork' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for triptych that I've seen before include "Hit crypt (anag) - painting" , "Altarpiece" , "work of art" , "Three-panelled painting" , "Three-panel artwork" .)