Definition of chalk

• n. - A soft, earthy substance, of a white, grayish, or yellowish white color, consisting of calcium carbonate, and having the same composition as common limestone.
• n. - Finely prepared chalk, used as a drawing implement; also, by extension, a compound, as of clay and black lead, or the like, used in the same manner. See Crayon.
• v. t. - To rub or mark with chalk.
• v. t. - To manure with chalk, as land.
• v. t. - To make white, as with chalk; to make pale; to bleach.