crack

1 of 3

verb

ˈkrak 

cracked; cracking; cracks

intransitive verb

1

: to make a very sharp explosive sound

The whip cracks through the air.

2

: to break, split, or snap apart

The statue cracked when she dropped it.

3

: fail: such as

a

: to lose control or effectiveness under pressure

—often used with up

The stress was so great that she started to crack up.

b

: to fail in tone

His voice cracked.

4

: to go or travel at good speed

—usually used with on

The steamboat cracked on.

transitive verb

1

a

: to break so that fissures appear on the surface

crack a mirror

b

: to break with a sudden sharp sound

crack nuts

2

: to tell especially suddenly or strikingly

crack a joke

3

: to strike with a sharp noise : rap

then cracks him over the head

cracked a two-run homer in the eighth

4

a(1)

: to open (something, such as a bottle) for drinking

(2)

: to open (a book) for studying

b

: to puzzle out and expose, solve, or reveal the mystery of

crack a code

c

: to break into

crack a safe

d

: to open slightly

crack the throttle

e

: to break through (something, such as a barrier) so as to gain acceptance or recognition

… on track to crack Hollywood after landing a big screen role.

—Ed Gleave and Peter Dyke

f

: to show or begin showing (a smile) especially reluctantly or uncharacteristically

5

a

: to impair seriously or irreparably : wreck

crack an opponent's courage

b

: to destroy the tone of (a voice)

c

: disorder, craze

Worry had cracked his otherwise cheerful disposition.

d

: to interrupt sharply or abruptly

The criticism cracked our complacency.

6

: to cause to make a sharp noise

cracks his knuckles

7

a(1)

: to subject (hydrocarbons) to cracking

(2)

: to produce by cracking

cracked gasoline

b

: to break up (chemical compounds) into simpler compounds by means of heat

crack

2 of 3

noun

1

a

: a loud roll or peal

a crack of thunder

b

: a sudden sharp noise

the crack of rifle fire

2

: a sharp witty remark : quip

3

a

: a narrow break : fissure

a crack in the ice

b

: a narrow opening

Leave the door open a crack.

cracks between floorboards

—used figuratively in phrases like fall through the cracks to describe one that has been improperly or inadvertently ignored or left out

a player who fell through the cracks in the college draft

Children slipping through the cracks of available youth services.

4

a

: a weakness or flaw caused by decay, age, or deficiency : unsoundness

b

: a broken tone of the voice

c

: crackpot

5

: moment, instant

the crack of dawn

6

: housebreaking, burglary

7

: a sharp resounding blow

gave him a crack on the head

8

: an attempt or opportunity to do something

her first crack at writing a novel

got first crack at the job opening

9

or crack cocaine : a potent form of cocaine that is obtained by treating the hydrochloride of cocaine with sodium bicarbonate to create small chips used illicitly for smoking

crack

3 of 3

adjective

: of superior excellence or ability

a crack marksman

Phrases

crack the whip

: to adopt or apply an authoritative, tyrannical, or threatening approach or policy (as in demanding harder work from employees)

The team needs a coach who isn't afraid to crack the whip.

crack wise

: to make a wisecrack

The comedian often cracked wise about prominent politicians.

Synonyms

Verb

• pop
• snap

Noun

• check
• chink
• cleft
• cranny
• crevice
• fissure
• rift
• split

Adjective

• accomplished
• ace
• adept
• compleat
• complete
• consummate
• crackerjack
• educated
• experienced
• expert
• good
• great
• master
• masterful
• masterly
• practiced
• practised
• professed
• proficient
• skilled
• skillful
• versed
• veteran
• virtuoso

Examples of crack in a Sentence

Verb

The hailstones were big enough to crack some windows.

He cracked his collarbone in a skiing accident.

The mirror cracked when she dropped it.

Workers cracked the large rock into three pieces so it could be moved.

The bird cracked the seed on a tree branch.

a tool used for cracking nuts

He cracked open the eggs.

Someone cracked him over the head with a beer bottle.

The baby cracked her chin pretty hard when she fell.

He fell and cracked his elbow on the ice.

Noun

The crack runs all the way from the top of the wall to the bottom.

an old patio with grass growing up through the cracks

The vase has a few fine cracks, but it is still usable.

I could see them through the crack in the doorway.

Light came through the cracks in the walls of the barn.

Adjective

The company has a crack sales force.

known as one of the college's crack tennis players

Recent Examples on the Web

Verb

Now, a May 15 report has brought another iPhone and Android warning to the forefront regarding PIN number usage: the speed at which AI can crack yours. —Davey Winder, Forbes.com, 20 May 2025

Imagine a slow-motion bubble of molten rock pressing upward beneath the surface, warping and cracking the crust above. —Victoria Corless, Space.com, 19 May 2025

Noun

Regularly inspect your property for gaps, cracks or open vents − areas that bees can squeeze into, Thompson said. —Greta Cross, USA Today, 20 May 2025

Once the plumbing leaks or a tile or grout cracks, water will seep behind bathroom tile and support the growth of mold. —Brandee Gruener, Southern Living, 20 May 2025

Word History

Etymology

Verb, Noun, and Adjective

Middle English crakken, from Old English cracian; akin to Old High German chrahhōn to resound

First Known Use

Verb

before the 12th century, in the meaning defined at intransitive sense 1

Noun

14th century, in the meaning defined at sense 1a

Adjective

1793, in the meaning defined above

Phrases Containing crack

• a fair crack of the whip
• a hard/tough nut (to crack)
• anti-crack
• at the crack of dawn
• crack a smile
• crack baby
• crack cocaine
• crack down
• crack house
• crack into
• crack shot
• crack up
• open a crack
• sand crack

Rhymes for crack

• ack
• brack
• clack
• dak
• flack
• flak
• hack
• jack
• knack
• lac
• lack
• lak

Kids Definition

crack

1 of 3 verb

ˈkrak 

1

a

: to break or cause to break with a sudden sharp sound : snap

b

: to make or cause to make such a sound

crack a whip

2

: to break with or without complete separation of parts

the ice cracked in several places

3

: to tell especially in a clever or witty way

crack jokes

4

a

: to lose control under pressure

—often used with up

b

: to fail in tone

her voice cracked

c

: to give or receive a sharp blow

cracked my head

5

a

: to puzzle out : solve

crack a code

b

: to break into or through

crack a safe

crack the sound barrier

6

a

: to put hydrocarbons through cracking

crack petroleum

b

: to produce by cracking

cracked gasoline

crack

2 of 3 noun

1

: a sudden sharp noise

2

: a sharp witty remark : quip

3

: a narrow break or opening

a crack in the glass

open the window a crack

4

a

: weakness sense 2, flaw

b

: a broken tone of the voice

5

: the beginning moment

the crack of dawn

6

: a sharp resounding blow

7

: try entry 2

take a crack at it

8

: highly purified cocaine in small chips used illegally usually for smoking

crack

3 of 3 adjective

: of high quality or ability

crack troops

Medical Definition

crack

noun

ˈkrak 

often attributive

: a potent form of cocaine that is obtained by treating the hydrochloride of cocaine with sodium bicarbonate to create small chips used illicitly usually for smoking