Criticises roofing material (6)
I believe the answer is:
slates
This might be a double definition.
'criticises' is the first definition.
Although both the answer and definition are verbs in their -s form, I can't understand how they can define each other.
'roofing material' is the second definition.
(I've seen this in another clue)
Can you help me to learn more?
(Other definitions for slates that I've seen before include "Criticises severely using roof coverings" , "Thin layers of rock for roofing" , "Strongly criticises the roof tiles" , "Berates with roofing tiles" , "Abuses with roof tiles?" .)