crack

crack — verb

1. if a hard surface like glass, bone, or dry earth cracks, or if a person or thing

1.verbtransitive / intransitiveB1
Definition

if a hard surface like glass, bone, or dry earth cracks, or if a person or thing cracks it, fine visible lines form on the outside while the object stays in one piece

Example

The old mirror in the hallway cracked after the door slammed against it.

intransitive: crack + [cause]

Layla noticed the paint had cracked on the ceiling above her desk.

Common collocations
  • crack under the weight
  • crack from the heat
  • crack in the wall
  • cracked glass
  • cracked mirror
Synonyms
  • fracture

    more formal, commonly used for bones or hard materials

  • split

    suggests a longer, more intentional break along a line

  • chip

    a small piece breaks off rather than a line appearing

Antonyms
  • seal

    to close or repair a crack

  • mend

    to repair something that has cracked

Grammar Patterns

crack

crack something

crack + adjunct of cause

Usage Note

Often used with an adjunct explaining the cause — crack under [weight/pressure/heat], crack from [impact/dryness].

Common Mistakes

I dropped the cup and it cracked into pieces.
I dropped the cup and it shattered into pieces.
crack means lines appear without separation; shatter means it breaks into many pieces.

2. if someone cracks after a long period of difficulty or stress, they become menta

2.verbintransitiveB2
Definition

if someone cracks after a long period of difficulty or stress, they become mentally or physically unable to continue functioning normally

Example

After weeks of working fifteen-hour days without a break, Hari finally cracked under the strain.

crack under the strain

The constant pressure from both family and work caused Élise to crack.

cause [someone] to crack

Common collocations
  • crack under pressure
  • crack under the strain
  • crack from stress
Synonyms
  • collapse

    more general; can be physical, mental, or structural

  • break down

    often implies a more dramatic emotional episode

  • snap

    sudden and complete loss of control, more informal

Antonyms
  • cope

    to deal successfully with pressure

  • endure

    to continue despite difficulty

Grammar Patterns

crack (under [pressure/strain/tension])

crack + and + [result clause]

Usage Note

Frequently followed by under + [strain/pressure/tension]. The subject is always a person or group of people; not used for machines or systems.

Common Mistakes

The computer cracked after the update.
The computer crashed after the update.
crack is for people experiencing mental exhaustion, not machines.

3. if a system, business, or organization cracks, it stops working or fails because

3.verbintransitiveB2
Definition

if a system, business, or organization cracks, it stops working or fails because of serious problems or outside pressure

Example

The company's old security system finally cracked after years of repeated cyber attacks.

Without proper government funding, the public health programme slowly began to crack.

intransitive: [system/organisation] + begin to crack

Common collocations
  • security system cracks
  • programme begins to crack
  • alliance cracks
Synonyms
  • collapse

    more sudden and complete failure

  • fail

    more general and neutral

  • break down

    implies gradual loss of function

Antonyms
  • hold

    to continue functioning despite pressure

  • stand firm

    to remain strong under challenge

Grammar Patterns

crack

begin to crack

crack under [pressure/weight]

Usage Note

Used metaphorically for systems, institutions, or processes, not for emotional states. Distinguish from sense 2 (MENTAL BREAKDOWN — for people) and sense 4 (GIVE IN — voluntary surrender).

4. if someone cracks in a difficult situation, they lose their emotional control an

4.verbintransitiveB2
Definition

if someone cracks in a difficult situation, they lose their emotional control and give up or admit the truth, especially after pressure or questioning

Example

The police questioned the suspect for six hours before he finally cracked and confessed.

During the tough negotiation, one lawyer cracked and accepted all of the other side's demands.

crack + and + [consequence]

Common collocations
  • crack under interrogation
  • crack and confess
  • finally crack
  • refuse to crack
Synonyms
  • give in

    more general; can be about any kind of surrender, not just under pressure

  • confess

    specifically about admitting guilt or truth

  • capitulate

    formal; surrendering after resistance

Antonyms

Grammar Patterns

crack (under [pressure])

crack + and + [action of surrender]

Usage Note

Often describes a specific moment of surrender under interrogation, negotiation, or punishment. Distinguish from sense 2 (MENTAL BREAKDOWN — general inability to function, not necessarily involving confession or surrender).

Common Mistakes

I cracked under pressure and cried.
I broke down under pressure and cried.
cracking under pressure in this sense implies giving in or confessing, not just showing emotion.

5. to forcefully break the outer shell or casing of something like a nut, an egg, o

5.verbtransitiveB1
Definition

to forcefully break the outer shell or casing of something like a nut, an egg, or a locked box so that you can take out what is inside

Example

Ari cracked the walnut with a small hammer and picked out the meat inside.

transitive: crack + [nut/food]

The burglars cracked the safe and took all the cash and jewellery inside.

Common collocations
  • crack an egg
  • crack a nut
  • crack a safe
  • crack open a bottle
Synonyms
  • crack open

    emphasises the action of separating the outer shell

  • break open

    more general; can be used for any container

  • split

    suggests a cleaner separation along a line

Antonyms
  • seal

    to close something shut

  • close

    opposite of opening

Grammar Patterns

crack something open

crack + [object with a hard shell/container]

Usage Note

Often used as crack open (+ object) for nuts, eggs, or containers. For bottles or drinks, use crack open rather than just crack.

Common Mistakes

She cracked the watermelon open with a knife.' (watermelons are cut, not cracked)
She cracked the coconut open with a heavy stone.
crack open is for hard-shelled objects.

6. to get into a computer system, network, or encrypted data without permission, us

6.verbtransitiveB2
Definition

to get into a computer system, network, or encrypted data without permission, usually to steal information, cause damage, or prove a skill

Example

A teenage hacker managed to crack the university's database and steal personal records.

The company hired a security expert to see if anyone could crack their network.

transitive: crack + [network/system]

Common collocations
  • crack a password
  • crack a code
  • crack into a system
  • crack encryption
  • crack the network
Synonyms
  • hack

    more common general term for breaking into systems

  • breach

    more formal; often used in security contexts

  • compromise

    formal; implies the system's security was weakened

Antonyms
  • secure

    to make a system safe against intrusion

  • protect

    to defend against unauthorised access

Grammar Patterns

crack + [computer system/network/code/password]

Usage Note

Informal computing term. More formal alternatives include breach or compromise. In everyday British English, hack is more common than crack for this sense.

Common Mistakes

The virus cracked my laptop.
A hacker cracked into my laptop.
crack is about unauthorised access, not about malware infection.

7. to make unauthorized copies of computer programs, films, or music, typically by

7.verbtransitiveB2
Definition

to make unauthorized copies of computer programs, films, or music, typically by removing or bypassing their copyright protection systems

Example

Dario cracked the game so his cousin could play it on his laptop.

crack + game/software/app (direct object)

The police arrested a man who had cracked thousands of songs and sold them online.

Common collocations
  • crack software
  • crack a game
  • crack a program
  • crack songs
  • crack movies
Synonyms
  • pirate

    more general; can refer to copying or distributing copyrighted material without permission

  • hack

    broader; 'hack' includes breaking into systems, while 'crack' specifically targets copyright protection

Grammar Patterns

crack + noun phrase (software/movie/song)

Usage Note

Commonly used in the context of digital piracy. The adjective form 'cracked' (e.g. 'cracked software') is also frequent and carries the same meaning.

Common Mistakes

I cracked the computer to see what was inside.
I cracked the software so I could use it without paying.
'crack' in this sense refers to bypassing copyright protection, not opening hardware.

8. to succeed in understanding a difficult puzzle, code, or crime by finding its hi

8.verbtransitiveB2
Definition

to succeed in understanding a difficult puzzle, code, or crime by finding its hidden meaning or solution

Example

A team of spies worked all night to crack the enemy's secret code.

crack + code/password/cipher

It took the detective nearly two years to crack the murder case.

Common collocations
  • crack a code
  • crack a case
  • crack a mystery
  • crack a puzzle
  • crack the problem
Synonyms
  • solve

    more general and neutral; does not carry the connotation of difficulty or secrecy

  • decipher

    specifically about decoding messages in a secret system

  • break

    used with 'code' (break a code); slightly more formal than 'crack'

Grammar Patterns

crack + noun (code/case/mystery/problem)

Usage Note

Subject is typically a person or group engaged in intellectual effort. The object is usually something hidden or mysterious (a code, a case, a puzzle), not a routine question.

Common Mistakes

I cracked my math homework in ten minutes.
I cracked the secret code in ten minutes.
'crack' suggests solving something difficult or mysterious, not ordinary homework.

9. to strike someone or something with a sudden, hard blow, often producing a sharp

9.verbtransitiveB2
Definition

to strike someone or something with a sudden, hard blow, often producing a sharp sound

Example

The tree branch cracked Reuben across the back as it swung down.

crack + person + across + body part

Heloísa cracked her elbow against the door frame and shouted in pain.

Common collocations
  • crack someone across the face/back/head
  • crack against the door/wall/table
Synonyms
  • rap

    less forceful; suggests a quick, light knock

  • smack

    similar force but focuses on the open-handed blow rather than the sound

Grammar Patterns

crack + someone/something + on/against + body part/object

Usage Note

Typically describes an accidental or forceful impact. The sound is an important part of the meaning — this is not used for a silent or gentle tap.

10. to produce a short explosive sound, or to cause an object to make such a noise

10.verbtransitive / intransitiveB1
Definition

to produce a short explosive sound, or to cause an object to make such a noise

Example

The lion tamer cracked his whip and the lions jumped onto their stools.

transitive: crack + whip

Amira heard the ice crack beneath her feet and quickly stepped back.

intransitive: ice/wood/ground + cracks

Common collocations
  • crack a whip
  • crack one's knuckles
  • crack one's joints
  • ice cracks
  • floorboards crack
Synonyms
  • snap

    usually refers to a thinner, higher-pitched sound (e.g. snapping fingers)

  • pop

    a softer, rounder explosive sound (e.g. a cork popping)

Grammar Patterns

transitive: crack + noun (whip/knuckles); intransitive: noun + cracks (ice/whip/firework)

Usage Note

Both transitive and intransitive uses are equally common. The sound is sharp and brief — not a continuous noise. 'Crack a whip' and 'crack one's knuckles' are fixed collocations.

11. when a person's voice changes pitch suddenly and without control because of a st

11.verbintransitiveB2
Definition

when a person's voice changes pitch suddenly and without control because of a strong feeling

Example

Ishaan's voice cracked with emotion as he read the letter from his daughter.

voice + crack + with + emotion/nerves/grief

The singer's voice cracked during the high note and the audience gasped.

Common collocations
  • voice cracks with emotion
  • voice cracks with nerves
  • voice cracks from crying
  • voice cracks mid-sentence
Synonyms
  • break

    similar meaning but less specific to pitch change; 'voice breaks' can also mean stopping altogether

  • waver

    suggests an unsteady trembling voice rather than a sudden pitch change

Grammar Patterns

voice + cracks + with + emotion (emotion/nerves/sorrow)

Usage Note

Only intransitive. The subject is always a voice or related noun (his voice, her voice, the speaker's voice). This sense is different from 'a voice that sounds rough from illness' — cracking here means a sudden break in pitch, not hoarseness.

Common Mistakes

He cracked his voice to sound more serious.
His voice cracked because he was so upset.
'crack' in this sense is intransitive and involuntary; you cannot deliberately crack your voice.

12. to say something humorous or witty, typically in a quick and offhand manner

12.verbtransitiveB2
Definition

to say something humorous or witty, typically in a quick and offhand manner

Example

My uncle is always cracking jokes at dinner and making everyone laugh.

collocation: crack a joke

Reuben cracked a joke about the food and everyone at the table laughed.

Common collocations
  • crack a joke
  • crack jokes
  • crack a witty remark
Synonyms
  • tell a joke

    more neutral in register; 'crack a joke' sounds quicker and more spontaneous

  • quip

    more formal and literary; suggests a short, clever remark rather than a structured joke

Grammar Patterns

crack + a joke

crack + funny remark/witty comment

Usage Note

Almost always used with the object 'a joke' or 'jokes'. 'Crack a joke' is a fixed collocation — it is far more common than the synonymous 'tell a joke' in informal speech.

Common Mistakes

I cracked a laughter.
I cracked a joke.
'crack a joke' is a fixed expression; you do not crack other things related to humour.

13. to use heat to break down the large hydrocarbon molecules in crude oil into smal

13.verbtransitive / intransitiveC1
Definition

to use heat to break down the large hydrocarbon molecules in crude oil into smaller, more useful ones such as petrol or diesel

Example

The refinery cracks crude oil into petrol, diesel, and jet fuel every day.

transitive: crack crude oil into [products]

Heavy oil cracked under high heat produces chemicals used for making plastics.

passive: oil + is cracked under high heat

Common collocations
  • crack crude oil
  • crack petroleum
  • crack hydrocarbons
  • crack into petrol
  • cracking process
Synonyms
  • refine

    broader; covers all stages of purifying crude oil, not just cracking

  • process

    more general; any treatment of raw materials

Grammar Patterns

crack [crude oil / petroleum] into [products]

crude oil / petroleum cracks into [products]

Usage Note

Technical term used in the petroleum and chemical engineering industries. The process itself is known as cracking or fluid catalytic cracking. Not encountered in everyday conversation.

Common Mistakes

The chemist cracked the compound by adding acid.' (too vague)
The refinery cracks crude oil by heating it to around 500°C.
this sense refers specifically to industrial petroleum processing, not general chemical breakdown.

14. to succeed at getting into a field, organisation, or level of achievement that h

14.verbtransitiveB2
Definition

to succeed at getting into a field, organisation, or level of achievement that has been very hard to reach, either because of rules, tradition, or bias

Example

Lotte became the first woman to crack the all-male board of directors at the bank.

transitive: crack + [exclusive group]

After years of effort, Samir finally cracked the Japanese market with his software product.

Common collocations
  • crack the market
  • crack the glass ceiling
  • crack the top ten
  • crack the barriers
  • crack an industry
Synonyms
  • break into

    phrasal verb, slightly more informal

  • penetrate

    more formal; suggests a forceful entry

  • enter

    neutral; does not imply difficulty

Antonyms

Grammar Patterns

crack + [barrier / market / glass ceiling / top ranking]

Usage Note

Commonly used with nouns such as market, barrier, glass ceiling, or top [ranking / ten / hundred]. The object is always something that was difficult to enter or achieve. Less common with concrete physical objects.

Common Mistakes

She cracked the door open to peek inside.
She opened the door a crack to peek inside.
this sense is metaphorical (barriers, markets, rankings); for physical openings use the noun crack or the phrasal verb crack open.
Phrasal verbs

crack down

phrasal verb

To take strong action to stop or control something, especially illegal activity.

The police cracked down on street racing last weekend.

Schools are cracking down on cheating during exams.

crack on

phrasal verb

To continue doing something with energy and determination.

Despite the rain, the workers cracked on with the building.

We cracked on with our studies after a short break.

crack on to

phrasal verb

To try to start a romantic or sexual relationship with someone.

Diego cracked on to his colleague at the party.

She felt uncomfortable when a stranger cracked on to her at the bar.

crack up

phrasal verb

To suddenly laugh a lot, or to cause someone to laugh a lot.

The comedian's joke made the audience crack up.

Aiden cracked up when he saw the funny video.

Idioms

To use your authority to make people work very hard, often by being strict.

The new manager cracks the whip to meet the deadline.

Did the coach crack the whip during practice yesterday?

To make jokes or humorous comments.

Maya loves to crack wise during lunch breaks.

He cracked wise about the broken printer, making everyone laugh.

To start doing something immediately and with energy.

We need to get cracking on the project now.

Sara got cracking on her homework right after dinner.

A problem or situation that is very difficult to solve or deal with.

This math problem is a tough nut to crack.

Finding a cure for the disease is a hard nut to crack.

To use much more force or effort than is needed for a task.

Sending a dozen workers to fix a small leak is using a sledgehammer to crack a nut.

Why use a sledgehammer to crack a nut when a simple tool works?

crack — noun

crack — adjective

Word family

  • cracker
    nounB2
  • cracking
    adjectiveB2
  • cracking
    nounC1
  • cracked
    adjectiveB1

Synonym discussion

Sense: verb/1

A crack is a narrow line that appears on a surface without the object falling apart — think of a cracked mirror you can still see your reflection in. To break means the object separates into pieces or stops working; breaking is more severe than cracking. A cracked vase might still hold water; a broken vase cannot. To split implies a cleaner, longer separation along a natural line — splitting wood along the grain, or splitting a team into groups. Fracture is the most formal and clinical term, used especially for bones and hard materials (a fractured femur, fractured rock). Use crack for fine surface lines, break for full separation, split for cutting along a plane, and fracture for formal or medical contexts.

breaksplitfracturecrack

Common collocations

Adverbs

  • crack under pressure
  • crack eventually
  • crack slowly
  • crack finally
  • crack easily

Phrases

  • a crack in the armour
  • at the crack of dawn
  • crack a smile (informal)
  • get cracking (informal, British)
  • a tough nut to crack
  • not all it's cracked up to be
  • crack down (on)
  • paper over the cracks
  • fall through the cracks

Prepositions

  • crack in [surface]
  • crack on [surface]
  • crack into [system/market]
  • crack open [container]
  • crack under [pressure/strain/weight]
  • crack from [heat/impact/dryness]

Nouns modified by crack

  • crack team
  • crack shot
  • crack unit
  • crack cocaine

Verbs with crack object

  • crack a joke
  • crack a code
  • crack a case
  • crack a nut
  • crack an egg
  • crack a safe
  • crack a whip
  • crack a password
  • crack the market
  • crack the glass ceiling
  • crack someone's skull (informal)

Verbs with crack subject

  • paint cracks
  • ice cracks
  • voice cracks
  • the system cracks
  • the foundation cracks

Etymology

GermanicOld EnglishMiddle EnglishEnglish

English crack comes from Old English cracian (to make a sharp noise), from a common Germanic root also found in Middle Dutch craken and German krachen. The core sense of a surface breaking without separating emerged in Middle English (1300s). The meaning extended metaphorically to mental collapse (1500s), then to cracking codes and solving puzzles (1600s). The adjective sense meaning "top-quality" comes from 18th-century British slang, originally describing boastful talk ("crack" as a noun for a tall tale). The computing senses (hacking, pirating software) date from the 1980s, and "crack cocaine" is named for the popping sound it makes when heated.