chalk

Definition
(noun) a soft whitish calcite Definition
(noun) a pure flat white with little reflectance Definition
(noun) an amphetamine derivative (trade name Methedrine) used in the form of a crystalline hydrochloride; used as a stimulant to the nervous system and as an appetite suppressant Definition
(noun) a piece of calcite or a similar substance, usually in the shape of a crayon, that is used to write or draw on blackboards or other flat surfaces Definition
(verb) write, draw, or trace with chalk