He chalked the stage to show the actors where they should stand.
First Known Use of CHALK
Medical Definition of CHALK
: a soft white, gray, or buff limestone composed chiefly of the shells of foraminifers and sometimes used medicinally as a source of calcium carbonate—called also creta; see precipitated chalk, prepared chalk
Soft, fine-grained, easily pulverized, white-to-grayish variety of limestone, composed of the shells of minute marine organisms. The purest varieties contain up to 99% calcium carbonate in the form of the mineral calcite. Extensive deposits occur in western Europe south of Sweden and in England, notably in the chalk cliffs of Dover along the English Channel. Other extensive deposits occur in the U.S. from South Dakota to Texas and eastward to Alabama. Chalk is used for making lime and portland cement and as a soil additive. Finely ground and purified chalk is known as whiting and is used as a filler, extender, or pigment in a wide variety of materials, including ceramics, putty, cosmetics, crayons, plastics, rubber, paper, paints, and linoleum. The chalk commonly used in classrooms is a manufactured substance rather than natural chalk.