chalk

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

chalk cliffs are not recommended for climbing

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

Tailor's chalk.

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

A platoon-sized group of airborne soldiers.

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

chalk your hands before climbing

After a leg stretch, we set off again at 11:30 hours in charge of U.S.A. No. 1736 (Miss Ohio had been chalked on her), a 2-8-0 utility engine.

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

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

To record a score or event, as if on a chalkboard.

This Book it chaulketh out before thine eyes / The man that ſeeks the everlaſting Prize: / It ſhevvs you vvhence he comes, vvhither he goes, / VVhat he leaves undone; alſo vvhat he does: / It alſo ſhovvs you hovv he runs, and runs, / Till he unto the Gate of Glory comes.

To manure (land) with chalk.

Land that is chalked

I then chalked the land at an expense of 4l. per acre, and planted potatoes, about ten bushels to the acre […]

A surname.

A suburban village attached to the east side of Gravesend, Gravesham borough, Kent, England (OS grid ref TQ6773).