chalk

American  

[chawk] / tʃɔk /

noun

1. a soft, white, powdery limestone consisting chiefly of fossil shells of foraminifers.

2. a prepared piece of chalk or chalklike substance for marking, as for writing on a blackboard.

3. a mark made with chalk.

4. a score or tally.

5. Sports Slang. the competitor considered most likely to win by the oddsmakers; favorite.

   If you don’t know anything about either team, just bet the chalk.

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verb (used with object)

1. to mark or write with chalk.

2. to rub over or whiten with chalk.

3. to treat or mix with chalk.

   to chalk a billiard cue.

4. to make pale; blanch.

   Terror chalked her face.

verb (used without object)

1. (of paint) to powder from weathering.

adjective

1. of, made of, or drawn with chalk.

verb phrase

1. chalk up

   1. to score or earn.

      They chalked up two runs in the first inning.

   2. to charge or ascribe to.

      It was a poor performance, but may be chalked up to lack of practice.

chalk British  

/ tʃɔːk /

noun

1. a soft fine-grained white sedimentary rock consisting of nearly pure calcium carbonate, containing minute fossil fragments of marine organisms, usually without a cementing material

2. a piece of chalk or a substance like chalk, often coloured, used for writing and drawing on a blackboard

3. a line, mark, etc made with chalk

4. billiards snooker a small cube of prepared chalk or similar substance for rubbing the tip of a cue

5. a score, tally, or record

6. informal totally different in essentials

7. informal by far

8. to be unable to judge or appreciate important differences

9. informal by no means; not possibly

10. (modifier) made of chalk

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verb

1. to draw or mark (something) with chalk

2. (tr) to mark, rub, or whiten with or as if with chalk

3. (intr) (of paint) to become chalky; powder

4. (tr) to spread chalk on (land) as a fertilizer

chalk Scientific  

/ chôk /

1. A soft, white, gray, or yellow limestone consisting mainly of calcium carbonate and formed primarily from the accumulation of fossil microorganisms such as foraminifera and calcareous algae. Chalk is used in making lime, cement, and fertilizers, and as a whitening pigment in ceramics, paints, and cosmetics. The chalk used in classrooms is usually artificial.

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Other Word Forms

• chalkiness noun
• chalklike adjective
• chalky adjective
• unchalked adjective

Etymology

Origin of chalk

First recorded before 900; Middle English chalk, schalk, calk, Old English cealc “plaster, cement”; cognate with Old Saxon calc, Dutch kalk, German Kalch, Kalk, from Latin calc- (stem of calx ) “lime, limestone, quicklime,” from Greek chálix “small stone, rubble, gravel, mortar”

Explanation

Chalk is a very soft kind of rock or limestone. While chalk is made of shells and the skeletons of sea creatures, it's usually found above sea level in pits or quarries. Chalk is made of the element calcium carbonite, and it has agricultural uses, as well as showing up (in tiny amounts) in both toothpaste and antacids. The kind of chalk that you use for writing on a blackboard or decorating the sidewalk was originally made from calcium carbonite, but modern writing chalk is more often made of gypsum, a related form of calcium. Chalk comes from the Latin calx, "limestone," with the Greek root khalix, "small pebble."

Example Sentences

But butterflies whose lifecycles are tied to specific habitats, such as woodland clearings or chalk grasslands, are struggling.

From BBC • Apr. 14, 2026

Pockets of chalk, clay and greensand encourage an exuberant spread of botanical life.

From The Wall Street Journal • Apr. 11, 2026

Residents of Southern California who see a mysterious streak in the nocturnal sky can chalk it up to another SpaceX launch.

From Los Angeles Times • Mar. 16, 2026

The South Downs National Park stretches across Hampshire, West Sussex and East Sussex, encompassing chalk hills and villages across the areas.

From BBC • Mar. 16, 2026

“I thought maybe you would know something about that, since you’re an artist, and chalk is your usual medium. Plus...”

From "Boy 2.0" by Tracey Baptiste

Related Words

• address
• compose
• create
• draft
• note
• pen
• print
• record
• rewrite
• scrawl
• scribble
• sign
• tell