Wood remains (3)
I believe the answer is:
ash
This clue is a double definition.
'wood' is the first definition.
(I've seen this before)
'remains' is the second definition.
(I've seen this before)
(Other definitions for ash that I've seen before include "Variety of tree" , "deposit" , "Tree - effect of burning" , "... for this maybe" , "Tree with pale wood" .)