Skirting (4)
I believe the answer is:
dado
'skirting' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for dado that I've seen before include "Differently finished lower part of an interior wall" , "Border along an inside wall" , "Wood border running round room walls" , "Architectural feature" , "Differently decorated lower part of an inside wall" .)