Construction material (8)
'construction material' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for concrete that I've seen before include "Not abstract - construction material" , "Solid, real" , "Actual - stuff made with cement" , "Unsightly building material" , "Substantial, real" .)
'construction material' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Another definition for masonite that I've seen is " Kind of hardboard made from pressed wood fibres".)