crack
crack — verb
1. if a hard surface like glass, bone, or dry earth cracks, or if a person or thing
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
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.
A rock hit the windshield and cracked the glass in front of the driver.
When the soil gets too dry during summer, it often cracks in several places.
文法句型
crack
crack something
crack + adjunct of cause
用法筆記
Often used with an adjunct explaining the cause — crack under [weight/pressure/heat], crack from [impact/dryness].
常見錯誤
2. if someone cracks after a long period of difficulty or stress, they become menta
if someone cracks after a long period of difficulty or stress, they become mentally or physically unable to continue functioning normally
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
Some soldiers who experience too much combat stress crack and need immediate medical support.
Obi knew he was close to cracking when he could no longer sleep at night.
- 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
文法句型
crack (under [pressure/strain/tension])
crack + and + [result clause]
用法筆記
Frequently followed by under + [strain/pressure/tension]. The subject is always a person or group of people; not used for machines or systems.
常見錯誤
3. if a system, business, or organization cracks, it stops working or fails because
if a system, business, or organization cracks, it stops working or fails because of serious problems or outside pressure
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
When the main hospital server cracked, doctors could not access any patient records.
Diya worried that the water supply system would crack if the drought continued.
- collapse
more sudden and complete failure
- fail
more general and neutral
- break down
implies gradual loss of function
- hold
to continue functioning despite pressure
- stand firm
to remain strong under challenge
文法句型
crack
begin to crack
crack under [pressure/weight]
用法筆記
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
if someone cracks in a difficult situation, they lose their emotional control and give up or admit the truth, especially after pressure or questioning
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]
After three days without proper sleep, the captured soldier cracked and revealed his unit's location.
João warned his team not to crack when the client started making unreasonable demands.
- 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
- hold out
to continue resisting
- stand firm
to refuse to give in
文法句型
crack (under [pressure])
crack + and + [action of surrender]
用法筆記
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).
常見錯誤
5. to forcefully break the outer shell or casing of something like a nut, an egg, o
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
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.
My grandmother always cracks two eggs into the bowl when she bakes a cake.
Owen cracked open a cold drink and sat down to watch the football game.
- 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
文法句型
crack something open
crack + [object with a hard shell/container]
用法筆記
Often used as crack open (+ object) for nuts, eggs, or containers. For bottles or drinks, use crack open rather than just crack.
常見錯誤
6. to get into a computer system, network, or encrypted data without permission, us
to get into a computer system, network, or encrypted data without permission, usually to steal information, cause damage, or prove a skill
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]
Law enforcement agencies now have special tools to crack encrypted messages quickly.
The security team found evidence that someone had tried to crack their email system.
- 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
文法句型
crack + [computer system/network/code/password]
用法筆記
Informal computing term. More formal alternatives include breach or compromise. In everyday British English, hack is more common than crack for this sense.
常見錯誤
7. to make unauthorized copies of computer programs, films, or music, typically by
to make unauthorized copies of computer programs, films, or music, typically by removing or bypassing their copyright protection systems
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.
Shirin warned her classmates that cracking movies from streaming sites breaks the law.
Running a website that offers cracked programs can lead to heavy fines.
文法句型
crack + noun phrase (software/movie/song)
用法筆記
Commonly used in the context of digital piracy. The adjective form 'cracked' (e.g. 'cracked software') is also frequent and carries the same meaning.
常見錯誤
8. to succeed in understanding a difficult puzzle, code, or crime by finding its hi
to succeed in understanding a difficult puzzle, code, or crime by finding its hidden meaning or solution
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.
Élise cracked the last puzzle of the game just before the time ran out.
Minho believed that cracking the problem of ocean plastic would need new ideas.
文法句型
crack + noun (code/case/mystery/problem)
用法筆記
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.
常見錯誤
9. to strike someone or something with a sudden, hard blow, often producing a sharp
to strike someone or something with a sudden, hard blow, often producing a sharp sound
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.
The baseball cracked Jin on the shoulder before he could raise his glove.
A delivery driver cracked his knee against the back of the truck.
文法句型
crack + someone/something + on/against + body part/object
用法筆記
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
to produce a short explosive sound, or to cause an object to make such a noise
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
Gabriel cracked his knuckles before he started typing his report.
The fireworks cracked loudly in the dark sky above the waiting crowd.
文法句型
transitive: crack + noun (whip/knuckles); intransitive: noun + cracks (ice/whip/firework)
用法筆記
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
when a person's voice changes pitch suddenly and without control because of a strong feeling
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.
Mira fought back tears but her voice cracked when she said goodbye.
Christopher's voice cracked with nerves during his first speech in front of the class.
文法句型
voice + cracks + with + emotion (emotion/nerves/sorrow)
用法筆記
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.
常見錯誤
12. to say something humorous or witty, typically in a quick and offhand manner
to say something humorous or witty, typically in a quick and offhand manner
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.
The comedian cracked several jokes during the show, but not all of them worked.
During the meeting, the manager cracked a joke about the broken printer.
- 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
文法句型
crack + a joke
crack + funny remark/witty comment
用法筆記
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.
常見錯誤
13. to use heat to break down the large hydrocarbon molecules in crude oil into smal
to use heat to break down the large hydrocarbon molecules in crude oil into smaller, more useful ones such as petrol or diesel
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
Luca studied how engineers crack petroleum into lighter fuels at the industrial plant.
The new cracking unit can process over sixty thousand barrels each day.
Without cracking, thick crude oil would be too heavy to use as vehicle fuel.
文法句型
crack [crude oil / petroleum] into [products]
crude oil / petroleum cracks into [products]
用法筆記
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.
常見錯誤
14. to succeed at getting into a field, organisation, or level of achievement that h
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
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.
The new streaming service struggled to crack a market already controlled by two big companies.
Hyun cracked the top ten rankings for the first time in her professional tennis career.
Young designers from smaller countries often find it hardest to crack the international fashion industry.
- break into
phrasal verb, slightly more informal
- penetrate
more formal; suggests a forceful entry
- enter
neutral; does not imply difficulty
- be excluded from
to be kept out of a group or field
- fail to enter
to be unsuccessful at gaining access
文法句型
crack + [barrier / market / glass ceiling / top ranking]
用法筆記
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.
常見錯誤
crack — noun
1. a thin line or narrow gap that appears on a surface when something has broken sl
a thin line or narrow gap that appears on a surface when something has broken slightly without coming apart
Romi noticed a long crack in the bathroom mirror after dropping a bottle near it.
collocation: crack in [surface]
Water leaked through a tiny crack in the old stone wall behind the kitchen sink.
The earthquake left a deep crack running across the road outside their apartment building.
Noor touched the crack in the wooden table and felt its rough edge.
Repair a crack in the ceiling before the rainy season makes it worse.
文法句型
there is a crack in [something]
用法筆記
Often paired with 'in' to specify which surface the crack appears on. A crack is shallower and narrower than a 'break' or 'split'.
常見錯誤
2. the narrow gap created when a door or window is moved just a little away from it
the narrow gap created when a door or window is moved just a little away from its closed position
Lotte opened the window a crack to let fresh air into the stuffy bedroom.
pattern: open [something] a crack
The cat slipped through the door when Benjamin left it open just a crack.
Morning light came through the curtain where Lara had pulled it apart a crack.
Yael sleeps with the bedroom door open a crack so the hallway light shines in.
文法句型
open [something] a crack
leave [something] a crack open
用法筆記
Almost always used in the phrase 'open [something] a crack' or '[something] is open a crack', where 'a crack' functions as an adverb of degree. Do not use 'a crack' as a standalone noun for this meaning.
3. a sudden, short, sharp sound like that of something breaking or a whip hitting a
a sudden, short, sharp sound like that of something breaking or a whip hitting a surface
A loud crack of thunder woke Nia from a deep sleep around three.
collocation: crack of thunder
The branch came down with a sharp crack and landed on the garden bench.
pattern: with a [adjective] crack
Jisoo heard the crack of the bat and knew the ball was a home run.
There was a sudden crack as the ice beneath Brian's boots began to break apart.
Ari flinched at the crack of the starting pistol during the school sports day.
文法句型
a crack of [something]
with a crack
用法筆記
This sense describes a short, dry, explosive sound — distinct from 'bang' (louder, deeper) or 'snap' (softer, higher-pitched). Often used with 'of' to identify the source of the sound.
4. an occasion when someone tries to do something, often for the first time or in a
an occasion when someone tries to do something, often for the first time or in a new situation
Ritu had never baked a cake but decided to have a crack at it for her mother's birthday.
pattern: have a crack at [something]
The manager asked if anyone wanted to take a crack at the payment system issue.
pattern: take a crack at [something]
Noor gave rock climbing a crack on holiday and discovered a new hobby.
Brian watched some videos and had a crack at fixing his broken bicycle chain.
文法句型
have a crack at [something]
give [something] a crack
take a crack at [something]
用法筆記
Always appears in fixed phrases like 'have a crack at', 'take a crack at', or 'give [something] a crack'. The object is whatever is being attempted. Common in everyday British, Australian, and New Zealand English.
常見錯誤
5. a powerfully addictive substance processed from cocaine, usually smoked in small
a powerfully addictive substance processed from cocaine, usually smoked in small crystals and illegal in most countries
The documentary showed how smoking crack can destroy a person's health quickly.
collocation: smoke crack
The city opened a new treatment centre to help people who became addicted to crack.
collocation: addicted to crack
Police arrested three people for selling crack near the school playground last Thursday night.
A health campaign warned teenagers about the dangers of crack cocaine.
- crack cocaine
the full, more formal name for this substance
文法句型
smoke crack
crack addict
crack cocaine
用法筆記
This sense refers specifically to crack cocaine, a smokable form processed from cocaine hydrochloride. It is chemically different from powdered cocaine and carries greater social stigma due to its association with severe addiction.
6. a word used in Ireland to describe enjoyable social time, lively conversation, a
a word used in Ireland to describe enjoyable social time, lively conversation, and a fun atmosphere among friends
The pub had live music that night, and the crack was brilliant until closing time.
pattern: the crack was [adjective]
Lara asked her colleagues where to find good crack in Dublin on a Friday.
collocation: good crack
The wedding had singing and dancing, and everyone said the crack was mighty.
At the festival, a local asked Benjamin, "What's the crack?"
- craic
the preferred modern Irish spelling
- fun
general term, less tied to Irish social culture
- entertainment
more formal, broader in meaning
文法句型
the crack was [adjective]
good crack
what's the crack?
用法筆記
This is the standard Irish English spelling 'craic', though it is often written as 'crack' in informal writing. It refers to atmosphere and entertainment — not to drugs or damage. The phrase 'what's the crack?' means 'how are things?' or 'what's happening?'. Avoid confusing this with any other sense of 'crack'.
常見錯誤
7. a technique or piece of software that lets someone enter a protected computer or
a technique or piece of software that lets someone enter a protected computer or network without permission in order to access data or carry out illegal actions
The security team found a crack that allowed outsiders to read private emails.
a crack + that-clause describing the exploit
Faisal downloaded a crack from a forum and tested it on his own server.
The company spent thousands fixing a crack in its payment system.
Many older websites had a well-known crack that hackers could use easily.
- exploit
a more technical term used by security professionals
- backdoor
a specific kind of secret entry method
- vulnerability
a weakness in a system that a crack can target
- patch
a software fix that removes a crack or vulnerability
文法句型
a crack (for [system])
use a crack
用法筆記
A countable noun used mainly in informal computing contexts. The more general term for the action is hack or exploit. Distinguish from verb sense 6 (HACK A SYSTEM — the action of breaking in), which is also computing slang.
常見錯誤
8. a short, clever, and often slightly critical comment that someone makes during a
a short, clever, and often slightly critical comment that someone makes during a conversation in order to be amusing or make a point
Kwame made a crack about the terrible cafeteria food, and everyone laughed.
make a crack about [topic]
Stephanie's crack about the team's slow progress embarrassed the manager.
A harmless crack about a colleague's haircut can still hurt their feelings.
Brandon could not resist a crack about the broken printer during the meeting.
- compliment
a positive remark with no critical edge
文法句型
make a crack (about [topic])
用法筆記
Usually paired with the verb make — make a crack (about something). Slightly more critical than a joke; a crack often targets a specific person, situation, or flaw. Do not confuse with crack meaning 'joke' in general — crack is shorter and sharper.
常見錯誤
crack — adjective
1. describes a person or thing that is exceptionally skilful or top-grade — for exa
describes a person or thing that is exceptionally skilful or top-grade — for example, a sports team, a military unit, or a performer who ranks among the very best.
A crack team of surgeons performed the operation at Tōkyō University Hospital.
crack + noun (team of professionals)
Zayd is a crack shot — he won the national title three years in a row.
crack + noun (shot = expert marksman)
The general put together a crack unit of experienced soldiers for the rescue mission.
Élise has a crack team of designers who create her fashion line every season.
- elite
more formal; used for groups rather than individuals ('an elite unit').
- top
broader meaning; less dramatic than 'crack' ('a top player').
- first-rate
slightly more formal; can be used predicatively ('this team is first-rate').
- expert
focuses on skill level rather than quality ('an expert pilot').
- mediocre
opposite in quality ('a mediocre team').
- second-rate
direct opposite, same register ('a second-rate unit').
文法句型
crack + noun
用法筆記
Only used before a noun (attributive position). Describes people or groups with exceptional skill. Common in British English in phrases such as 'crack shot' (expert marksman), 'crack regiment,' or 'crack team.' Not used in American English in this sense.