1. 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
   "The teacher wrote the maths equation on the blackboard with a piece of chalk"
    
2. A soft whitish calcite
   "The teacher wrote on the blackboard with chalk"
    
3. A pure flat white with little reflectance
   "The chalk cliffs stood out starkly against the blue sea"
    
4. [informal] 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
   "chalk abuse has become a serious problem in many communities";
   - methamphetamine, methamphetamine hydrochloride, Methedrine, meth [informal], deoxyephedrine, crank [informal], glass [informal], ice [informal], shabu [Asia, informal], trash [informal], tik [S.Africa], crystal meth, crystal [informal]

1. Write, draw, or trace with chalk
   "The teacher chalked the equation on the blackboard"
    
2. [informal] Achieve or record (a success or achievement)
   "The team chalked up another victory";
   - chalk up [informal]

Derived forms: chalks, chalking, chalked

Type of: amphetamine, calcite, controlled substance, draw, pep pill [informal], speed [informal], upper [informal], white, whiteness, writing implement

Encyclopedia: Chalk, Gary