Scottish. The crown of a road. Obsolete. rare.

Originally Scottish. Broken stone for use in road-building, or (occasionally) as ballast for railway lines. Also in plural. Now chiefly in road metal…

broken stone used in making roads.

Usually in plural: a stone used for making roads. Also as a mass noun: a quantity of this; a type of stone used in road-making.

Road metal; = metal, n. 10. Also: the process of making or mending roads with road metal. Cf. road metalling n. at road, n. compounds 6.

the material used for making or mending roads with metal (metal, n. 10); (also) the action or process of surfacing roads with this.

Building. Broken bricks, rubble, or similar solid material used as a filling or foundation.