A stone for building; a stone forming part of a wall. Also, in generalized sense, masonry; stone suitable for building; spec. see quot. 1870. Also…

concrete in technical use (see 2b). A block or slice of stone of a fixed size; also collective singular, stone cut into scantlings.

spec. A solid piece of stone, etc., prepared for building purposes; also the ‘bricks’ with which children build toy-houses.