Definition of "chalk" in English

noun

1. (uncountable) A soft, white, powdery limestone (calcium carbonate, CaCO₃).

   • chalk cliffs are not recommended for climbing

2. (countable) A piece of chalk, or nowadays processed compressed gypsum (calcium sulfate, CaSO₄), that is used for drawing and for writing on a blackboard (chalkboard).

   • the chalk used to write on the blackboard makes a squeaky sound

3. Tailor's chalk.

4. (uncountable, climbing, gymnastics) A white powdery substance used to prevent hands slipping from holds when climbing, or losing grip in weight-lifting or gymnastics, sometimes but not always limestone-chalk, often magnesium carbonate (MgCO₃).

   • when working out your next move, it's a good idea to get some more chalk from the bag

5. (US, military, countable) A platoon-sized group of airborne soldiers.

6. (US, sports, chiefly basketball, horse racing) The favorite in a sporting event.

7. (US, sports, chiefly basketball) The prediction that there will be no upsets, and the favored competitor will win.

verb

1. To apply chalk to anything, such as the tip of a billiard cue.

   • chalk your hands before climbing

2. To record something, as on a blackboard, using chalk.

3. To use powdered chalk to mark the lines on a playing field.

4. (figurative) To record a score or event, as if on a chalkboard.

5. To manure (land) with chalk.

6. To make white, as if with chalk; to make pale; to bleach.