Condemn building material (5)
I believe the answer is:
slate
This might be a double definition.
'condemn' is the first definition.
Although both the answer and definition are verbs in their base form, I can't understand how one could define the other.
'building material' is the second definition.
(slate is a kind of building material)
Can you help me to learn more?
(Other definitions for slate that I've seen before include "Stone used for roofing" , "Grey stone; tab" , "Roofing plate" , "Rubbish" , "rock used in building" .)