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유출하다

B2 verb #4,000 most common 9 min read

유출하다

yuchulhada Top 4,000

Practice it Examples Notes & Tips 유출하다 in 30 Seconds

Explanation 유출하다 in your Level:

At the A1 level, '유출하다' is a very difficult and advanced word. You don't need to use it in daily conversation yet. However, you might see it on signs or in simple news headlines. Think of it as a special word for 'water coming out' or 'information coming out' when it shouldn't. At this level, just remember that '유' means 'flow' and '출' means 'out'. If you see '유출', something is flowing out where it doesn't belong. For simple things like a leaky water bottle, you should use '새다' (sae-da) instead. '유출하다' is for big, serious things like a lot of oil in the ocean or many people's phone numbers being stolen. It is a 'Level 10' word for a 'Level 1' student, so don't worry if it feels hard!

At the A2 level, you should start to recognize '유출하다' in the context of the news. You might hear about '개인정보 유출' (gae-in-jeong-bo yu-chul), which means 'personal information leak'. This is a common topic in Korea. When you use this word, you are talking about something serious. It's not for a small mistake. It's for when a company or a person lets something important get out to the public. For example, if a student steals the answers to a test and gives them to friends, that is '시험 문제 유출' (test question leak). Remember the structure: [Thing] + 을/를 + 유출하다. It is a formal word, so use it when you want to sound serious about a problem.

At the B1 level, you should be able to distinguish between '유출하다' (to leak something) and '유출되다' (to be leaked). This is an important grammar point. If you say '회사가 정보를 유출했다', it means the company (the subject) did the action. If you say '정보가 유출되었다', it means the information was the victim of the leak. You will see this word often in intermediate reading materials about the environment (기름 유출 - oil spill) or technology. You should also start to notice the Hanja roots: 流 (flow) and 出 (out). This will help you understand related words like '수출' (export - flow out to another country) and '수입' (import - flow in).

At the B2 level, you are expected to use '유출하다' accurately in essays and discussions about social issues. This word is essential for talking about 'industrial espionage' (기술 유출) and 'capital flight' (자본 유출). You should understand its nuance compared to '누설하다' (leaking a spoken secret) or '방출하다' (releasing/emitting). At this level, you should be comfortable using it in complex sentences with connectors like '~음으로써' (by doing) or '~기 때문에' (because). For example: '기업 기밀을 유출함으로써 막대한 손해를 입혔다' (By leaking corporate secrets, they caused enormous damage). You should also know the noun form '유출' and how it combines with other nouns to form compound terms used in business and law.

At the C1 level, you should master the abstract and metaphorical uses of '유출하다'. This includes '인재 유출' (brain drain) and '국부 유출' (drain of national wealth). You should be able to discuss the socio-economic implications of these phenomena. Your usage should reflect an understanding of the formal register; you would use this word in a legal brief, a scientific report, or a high-level political debate. You should also be aware of the specific legal terminology surrounding '유출', such as '고의적 유출' (intentional leak) versus '과실에 의한 유출' (leak due to negligence). Your ability to use this word correctly in writing will demonstrate a high level of literacy and professional Korean proficiency.

At the C2 level, '유출하다' is a tool for precise expression in professional and academic discourse. You should be able to analyze the nuances between '유출', '발설', '누설', and '공표' in a legal or literary context. You might encounter this word in classical-style modern prose or high-level philosophical texts discussing the 'outflow' of energy or spirit. At this level, you are expected to not only use the word correctly but also to understand the historical development of the term and its Hanja variants. You should be able to spontaneously use it in high-pressure environments like televised debates or academic presentations, maintaining the correct honorifics and formal sentence structures that typically accompany such a high-register Sino-Korean verb.

Practice it Examples Notes & Tips

유출하다 in 30 Seconds

A formal verb meaning to leak or discharge information, liquids, or resources outside intended boundaries.
Commonly used for data breaches (정보 유출) and environmental spills (기름 유출).
Implies an active or systemic failure rather than just a natural drip.
Essential for professional, news, and academic contexts in Korean.

The Korean verb 유출하다 (yuchul-hada) is a sophisticated term primarily used to describe the act of something flowing out or being leaked from a controlled environment to the outside. It is a Sino-Korean word composed of the Hanja characters 流 (유 - to flow) and 出 (출 - to go out), combined with the active verb ending 하다 (to do). While it can physically refer to the discharge of liquids like oil or chemical waste, its most frequent usage in modern Korean society pertains to the unauthorized release of digital information, personal data, or state secrets. Understanding this word requires recognizing the distinction between a natural leak and a systemic failure or intentional act of spreading restricted content.

Information Security Context: This is arguably the most common context today. When a company experiences a data breach where customer names, phone numbers, or passwords are stolen and spread online, the media uses the term '개인정보 유출' (personal information leak). Here, '유출하다' describes the action—often by a hacker or a negligent employee—of letting that data out into the public or onto the dark web.

해커들이 기업의 기밀 문서를 외부로 유출했다.

Translation: Hackers leaked the company's confidential documents to the outside.

Environmental and Industrial Context: In industrial settings, the word describes the discharge of substances. If a tanker spills oil into the ocean, or a factory releases toxic chemicals into a river, '유출하다' is the formal verb used to describe this action. It carries a sense of gravity and environmental impact that simpler words for 'leak' do not possess.

Economic and Human Resource Context: Beyond physical and digital items, '유출하다' can apply to abstract concepts like capital or talent. '자본 유출' refers to capital flight, where money leaves a country's economy. '인재 유출' refers to the 'brain drain' phenomenon, where highly skilled individuals leave their home country to work abroad. In these cases, the 'container' is the national boundary or the domestic market.

그 회사는 핵심 기술을 해외로 유출한 직원을 고소했다.

Translation: The company sued the employee who leaked core technology abroad.

In summary, '유출하다' is a versatile verb used across law, technology, environmental science, and economics. It suggests a breach of trust, a failure of containment, or a significant loss for the originating entity. Whether it is a secret recipe, a million liters of crude oil, or billions of dollars in investment, if it moves out of its intended place in a problematic way, '유출하다' is the word of choice for Korean speakers.

Using 유출하다 correctly involves understanding its transitive nature. Since it is an active verb (ending in -하다), it requires an object—the thing being leaked—marked with the object particles 을 or 를. Furthermore, it often appears with the particle ~로 (to/towards) to indicate where the leaked material is going, or ~에서 (from) to indicate the source. Mastering these patterns allows you to describe complex scenarios like corporate espionage or environmental accidents with precision.

Grammatical Structure 1: [Object] + 을/를 유출하다: This is the most basic form. You identify the substance or information being moved. For example, '정보를 유출하다' (to leak information) or '기름을 유출하다' (to leak oil). This structure focuses on the action performed by the subject.

공장 측은 고의로 폐수를 강에 유출하지 않았다고 주장했다.

Translation: The factory claimed they did not intentionally discharge wastewater into the river.

Grammatical Structure 2: [Direction] + 로 유출하다: When you want to emphasize where the leak is headed, use the direction particle '~로' (to/towards) or '외부로' (to the outside). This is very common in news reports discussing data breaches where information is sent to 'foreign countries' (해외로) or 'competitors' (경쟁사로).

Grammatical Structure 3: [Subject] + 이/가 [Object] + 을/를 유출하다: In formal writing, the subject is often a person, a group, or an entity. '정부가 기밀을 유출하다' (The government leaks secrets). If the subject is an inanimate object causing the leak, like a pipe, '유출하다' can still be used, but '유출되다' or '새다' is often preferred for natural accidents.

그 직원은 돈을 받고 고객 명단을 경쟁 업체에 유출했습니다.

Translation: That employee took money and leaked the customer list to a competitor.

When practicing this word, try to vary the objects. Instead of just 'information', think about 'gas' (가스), 'radioactive material' (방사능 물질), or even 'exam questions' (시험 문제). Each of these changes the gravity of the sentence. Remember that '유출하다' is almost always associated with a negative outcome or a violation of rules, so it is rarely used in a positive or casual context like 'leaking a surprise party' (for which '누설하다' or '말해버리다' is better).

You are most likely to encounter 유출하다 in formal settings such as news broadcasts, newspaper articles, and legal documents. It is a 'hard' word that sounds professional and serious. Because Korea is a highly digitized society, '개인정보 유출' (personal information leak) is a term that appears in the news almost weekly. Whether it's a shopping mall being hacked or a government database being accessed improperly, this word is the standard descriptor for such events.

News and Media: News anchors will use this word when reporting on scandals. For instance, if a famous actor's private photos are spread online without consent, the news might report that someone '사진을 유출했다' (leaked the photos). If a politician leaks a classified document to a reporter, they '기밀을 유출했다'.

'뉴스 속보: 대형 포털 사이트에서 회원 천만 명의 비밀번호가 유출되었습니다.'

Translation: 'Breaking News: Passwords of 10 million members have been leaked from a large portal site.'

Corporate and Legal Environments: In a Korean office, you might see posters warning against '기술 유출' (technology leak). Companies like Samsung or SK Hynix are extremely sensitive about their semiconductor technology being leaked to foreign competitors. Employment contracts often include clauses about the consequences of '유출하다' (leaking) trade secrets.

Environmental Activism and Governance: When environmental groups protest against pollution, they use '유출하다' to describe companies dumping waste. You might hear it in documentaries about the 'Hebei Spirit' oil spill (태안 기름 유출 사고), which was one of the largest environmental disasters in Korean history. The word emphasizes the massive scale and the negligence involved.

방사능 오염수를 바다로 유출하는 행위는 전 지구적인 범죄입니다.

Translation: The act of discharging radioactive contaminated water into the sea is a global crime.

Finally, in academic or economic discussions, you will hear about '자본 유출' (capital flight) during financial crises. When investors lose confidence in the Korean Won and move their money to the US Dollar or Gold, experts discuss how to prevent capital from '유출하다'. In every context, the word carries a weight of 'loss' and 'uncontrolled movement' that demands attention.

The most common mistake learners make with 유출하다 is using it in contexts that are too casual or for small-scale physical leaks. While it means 'to leak', it is not interchangeable with every English sense of the word. Understanding the nuances of formality and agency is key to avoiding awkward sentences.

Mistake 1: Using it for small, natural leaks: If your water bottle is leaking in your bag, do not say '물이 유출해요'. This sounds like your water bottle is a major industrial facility or a hacker. Instead, use the word 새다 (saeda). '새다' is the general word for something leaking through a hole or crack. '유출하다' implies a much larger scale or a violation of a boundary.

❌ 천장에서 물이 유출하고 있어요. (Wrong scale/formality)
✅ 천장에서 물이 새고 있어요. (Correct: The ceiling is leaking.)

Mistake 2: Confusing Active (유출하다) and Passive (유출되다): Many students say '정보가 유출했어요' when they mean 'The information was leaked'. However, '유출하다' requires a subject that *does* the leaking. If the information is the subject, you must use the passive form 유출되다. '정보가 유출되었어요' means 'The information was leaked', whereas '누군가 정보를 유출했어요' means 'Someone leaked the information'.

Mistake 3: Using it for 'Spoilers': In English, we say 'leaked footage' or 'leaked plot points'. While '유출하다' can be used for leaked movie files (파일 유출), it is rarely used for just telling someone the ending of a movie. For spoilers, Koreans use 스포하다 (spo-hada) or 누설하다 (nuseol-hada). '유출하다' sounds like a corporate crime, not a social faux pas.

❌ 친구가 영화 결말을 유출했어요. (Too formal/serious)
✅ 친구가 영화 결말을 스포했어요. (Correct: My friend spoiled the movie.)

By keeping the scale (large/formal) and the intent (often unauthorized/illegal) in mind, you can avoid these common pitfalls. Always ask yourself: 'Is this a news-worthy event?' If yes, '유출하다' is likely appropriate. If it is a small everyday annoyance, look for a simpler verb.

To truly master 유출하다, you must see how it sits alongside other Korean words for 'leaking' or 'releasing'. Korean has a rich vocabulary for movement, and choosing the wrong word can change your meaning from 'industrial espionage' to 'a dripping faucet'.

유출하다 vs. 누설하다 (Nuseol-hada): Both mean 'to leak secrets', but 누설하다 focuses purely on information and speech. You '누설' a secret (비밀을 누설하다). 유출하다 is broader—it can involve physical objects, data files, or liquids. If you tell a secret, it's '누설'. If you send a database file to a competitor, it's '유출'.

유출하다 vs. 새다 (Saeda): 새다 is a pure Korean word (native). It is used for natural, accidental leaks. Water leaking from a pipe, air leaking from a tire, or a secret 'getting out' naturally. 유출하다 is a Sino-Korean word used for formal, large-scale, or illegal outflows. '새다' is passive/natural; '유출하다' is often active/systemic.

비밀이 샜다 vs. 정보를 유출했다.

The secret got out (naturally) vs. Someone leaked the information (actively).

유출하다 vs. 방출하다 (Bangchul-hada): 방출하다 means 'to emit' or 'to release'. It is often used for energy (heat, light) or releasing athletes from a team. While '유출하다' implies something *escaping* that shouldn't have, '방출하다' often implies a controlled or intentional release (though it can be negative in environmental contexts, like '방사능 방출').

유출하다 vs. 유포하다 (Yupo-hada): 유포하다 means 'to circulate' or 'to spread' (usually rumors or viruses). If a hacker *leaks* a file, they '유출' it. If they then *spread* it to thousands of people, they '유포' it. '유출' is the exit from the source; '유포' is the wide distribution afterward.

허위 사실을 유포하는 것은 법적으로 금지되어 있습니다.

Spreading (circulating) false information is legally prohibited.

Choosing between these words depends on the nature of the 'leak'. If it's a high-stakes situation involving data or industrial materials, '유출하다' is your safest and most accurate bet. If it's a whispered secret among friends, stick to '누설하다' or '말하다'.

How Formal Is It?

Fun Fact

The character 流 (유) is the same one used in 'Hallyu' (Korean Wave), meaning the 'Korean Flow'. So, '유출하다' is literally the 'outflow' of that stream.

Pronunciation Guide

UK /ju.tɕʰul.ɦa.da/

US /ju.tʃʰul.hɑ.dɑ/

Stress is usually neutral across syllables in Korean, but a slight emphasis may fall on 'chul'.

Rhymes With

수출하다 (export) 매출하다 (sell) 압출하다 (extrude) 추출하다 (extract) 일출하다 (sunrise) 탈출하다 (escape) 제출하다 (submit) 연출하다 (direct)

Common Errors

Pronouncing 'chul' as 'chool' like 'school'. It should be shorter.
Mumbling the 'h' in 'hada'. It should be clearly audible but soft.
Confusing 'yu' with 'yo'.

Difficulty Rating

Reading 4/5

Common in news, but requires knowledge of Hanja-based vocabulary.

Writing 5/5

Requires correct use of particles (~을/를) and distinguishing from passive form.

Speaking 4/5

Used in professional debates or when discussing serious news.

Listening 4/5

Frequently heard in news broadcasts and documentaries.

What to Learn Next

Prerequisites

나가다 (to go out) 나오다 (to come out) 물 (water) 정보 (information) 비밀 (secret)

Learn Next

누설하다 (to leak secrets) 방출하다 (to emit) 유입하다 (to flow in) 수출하다 (to export)

Advanced

공표하다 (to officially announce) 폭로하다 (to disclose/expose) 은닉하다 (to hide/conceal)

Grammar to Know

Active vs Passive (-하다 vs -되다)

정보를 유출하다 (Active) vs 정보가 유출되다 (Passive)

Causative (-시키다)

정보를 유출시키다 (To cause/make information leak)

Nominalization (-ㄴ/은/는 것)

정보를 유출하는 것은 범죄다.

Reason/Cause (-어서/아서)

기름을 유출해서 바다가 오염되었다.

Intent (-으려고)

돈을 벌려고 기술을 유출했다.

Examples by Level

기름이 바다로 유출했다.

Oil leaked into the sea.

Simple subject-object-verb structure.

정보를 유출하지 마세요.

Please do not leak information.

-지 마세요 (Please don't).

물이 밖으로 유출했다.

Water leaked outside.

밖으로 (to the outside).

누가 비밀을 유출했어?

Who leaked the secret?

Interrogative with '누가' (who).

가스가 유출하고 있어요.

Gas is leaking.

-고 있다 (Present progressive).

그는 사진을 유출했다.

He leaked the photo.

Past tense -했다.

회사가 돈을 유출했다.

The company leaked (lost) money.

Company as the subject.

유출한 사람은 누구입니까?

Who is the person who leaked it?

Adjective form -한 (who did).

해커가 내 비밀번호를 유출했다.

A hacker leaked my password.

Subject is '해커' (hacker).

시험 문제를 유출하면 안 됩니다.

You must not leak test questions.

-면 안 되다 (Must not).

공장에서 폐수를 유출했습니다.

The factory discharged wastewater.

Formal -습니다 ending.

개인정보를 유출한 사이트를 조심하세요.

Be careful of sites that leaked personal information.

Relative clause '유출한 사이트'.

실수로 이메일을 외부로 유출했다.

I leaked the email to the outside by mistake.

실수로 (by mistake).

그들은 기밀 서류를 유출했다.

They leaked confidential documents.

Plural subject '그들'.

뉴스는 기름이 유출했다고 보도했다.

The news reported that oil leaked.

Indirect speech -고 보도했다.

데이터를 유출하지 않도록 주의하세요.

Be careful not to leak data.

-지 않도록 (so that... not).

고객의 전화번호를 유출한 직원이 잡혔다.

The employee who leaked customers' phone numbers was caught.

Passive verb '잡혔다' (was caught) combined with active '유출한'.

정부는 방사능 물질을 유출한 기업을 처벌했다.

The government punished the company that leaked radioactive material.

Complex subject and object.

기술을 해외로 유출하는 것은 범죄입니다.

Leaking technology abroad is a crime.

-는 것 (nominalization).

어떻게 정보를 유출했는지 조사 중이다.

They are investigating how the information was leaked.

-는지 조사 중이다 (investigating how...).

그는 고의로 내부 기밀을 유출했다고 고백했다.

He confessed that he intentionally leaked internal secrets.

고의로 (intentionally).

회사는 정보 유출을 막기 위해 노력하고 있다.

The company is making efforts to prevent information leaks.

-기 위해 (in order to).

독성 물질을 유출하면 환경에 해롭습니다.

If you leak toxic substances, it is harmful to the environment.

Conditional -면.

그 영화사는 예고편을 미리 유출했다.

The movie studio leaked the trailer in advance.

미리 (in advance).

핵심 기술을 유출한 혐의로 구속 기소되었다.

He was arrested and indicted on charges of leaking core technology.

Legal terminology: 혐의 (charge), 구속 기소 (arrest and indictment).

외환 위기 당시 막대한 자본이 해외로 유출했다.

During the foreign exchange crisis, enormous capital flowed abroad.

Economic context: 자본 유출 (capital flight).

이번 사건은 관리자가 정보를 유출하면서 시작되었다.

This incident began as the manager leaked information.

-면서 (while/as).

유출한 데이터의 양이 예상보다 훨씬 많았다.

The amount of leaked data was much larger than expected.

-보다 훨씬 (much more than).

국가 기밀을 유출하는 행위는 반역죄에 해당한다.

The act of leaking state secrets constitutes treason.

~에 해당하다 (to correspond to/constitute).

그는 경쟁 업체에 유리한 정보를 유출했다.

He leaked information that was advantageous to the competitor.

유리한 정보 (advantageous information).

기름을 유출한 선박의 선장은 책임을 회피했다.

The captain of the ship that leaked oil evaded responsibility.

책임을 회피하다 (to evade responsibility).

시스템의 허점을 이용해 정보를 유출했다.

They leaked information by exploiting a loophole in the system.

허점 (loophole/weak point).

인재가 해외로 유출하는 현상은 국가 경쟁력을 약화시킨다.

The phenomenon of talent leaking abroad weakens national competitiveness.

Abstract usage: 인재 유출 (brain drain).

수사 기관은 누가 정보를 유출했는지 끝까지 추적할 방침이다.

Investigative agencies plan to track down who leaked the information to the very end.

~할 방침이다 (to plan/intend to).

기업들은 산업 스파이에 의한 기술 유출을 방지하기 위해 보안을 강화하고 있다.

Companies are strengthening security to prevent technology leaks by industrial spies.

산업 스파이 (industrial spy).

검찰은 그가 수사 기밀을 유출했다고 판단하고 수사를 확대했다.

The prosecution expanded the investigation, judging that he leaked investigative secrets.

-고 판단하다 (to judge that...).

방사능 오염수를 고의로 유출했다는 의혹이 제기되었다.

Suspicions were raised that radioactive contaminated water was intentionally discharged.

의혹이 제기되다 (suspicions were raised).

자본이 급격히 유출하면서 국내 증시가 폭락했다.

As capital leaked out rapidly, the domestic stock market crashed.

급격히 (rapidly).

그는 자신의 지위를 이용해 내부 정보를 외부로 유출했다.

He leaked internal information to the outside by using his position.

지위를 이용해 (using one's position).

정보를 유출한 배후 세력을 밝혀내는 것이 시급하다.

It is urgent to identify the forces behind the information leak.

배후 세력 (forces behind/mastermind).

국부 유출을 막기 위한 다각적인 정책적 노력이 필요하다.

Multifaceted policy efforts are needed to prevent the drain of national wealth.

국부 유출 (drain of national wealth).

그는 조직의 이익을 배반하고 핵심 정보를 유출하는 만행을 저질렀다.

He committed the barbaric act of betraying the organization's interests and leaking core information.

Strong vocabulary: 만행 (barbaric act), 저질렀다 (committed).

해당 공기업은 민감한 고객 데이터를 유출함으로써 공신력에 치명적인 타격을 입었다.

By leaking sensitive customer data, the public enterprise suffered a fatal blow to its public credibility.

공신력 (public credibility), 치명적인 타격 (fatal blow).

기술 유출은 단순한 기업 간의 경쟁을 넘어 국가 안보를 위협하는 사안이다.

Technology leakage is an issue that goes beyond simple competition between companies and threatens national security.

~를 넘어 (beyond).

정보를 유출한 혐의자가 묵비권을 행사하며 수사에 협조하지 않고 있다.

The suspect accused of leaking information is exercising their right to remain silent and not cooperating with the investigation.

묵비권 (right to remain silent).

환경 단체는 공장이 유독 가스를 유출했다고 주장하며 강력한 처벌을 요구했다.

Environmental groups demanded strong punishment, claiming the factory leaked toxic gas.

유독 가스 (toxic gas).

데이터 유출 사고에 대한 기업의 사후 대응이 미흡하다는 지적이 잇따르고 있다.

There are successive criticisms that companies' follow-up responses to data leak accidents are insufficient.

사후 대응 (follow-up response), 미흡하다 (insufficient).

그 학자는 자신의 연구 성과가 공식 발표 전에 유출한 것에 대해 분노했다.

The scholar was enraged that their research results were leaked before the official announcement.

연구 성과 (research results).

Synonyms

누설하다 방출하다 흘리다 빼돌리다

Antonyms

유입하다 보존하다

Common Collocations

정보를 유출하다

기밀을 유출하다

기름을 유출하다

자본을 유출하다

기술을 유출하다

폐수를 유출하다

시험 문제를 유출하다

명단을 유출하다

외부로 유출하다

고의로 유출하다

Common Phrases

개인정보 유출

— Personal information leak. Refers to data breaches.

개인정보 유출 사고가 발생했다.

기밀 유출

— Leak of confidential information.

기밀 유출은 심각한 범죄다.

기름 유출

— Oil spill.

바다에서 기름 유출 사고가 났다.

기술 유출

— Technology leak/espionage.

기술 유출 방지가 중요하다.

자본 유출

— Capital flight/outflow.

자본 유출로 경제가 어렵다.

인재 유출

— Brain drain.

국내 인재 유출이 심각하다.

명단 유출

— Leaking a list (usually customers or members).

회원 명단 유출을 조사 중이다.

시험 문제 유출

— Leaking exam questions.

시험 문제 유출로 재시험을 본다.

폐수 유출

— Wastewater discharge.

폐수 유출 공장을 신고했다.

가스 유출

— Gas leak.

가스 유출 사고에 주의하세요.

Often Confused With

유출하다 vs 새다

Use '새다' for small, natural, or accidental leaks (like a roof or a small secret).

유출하다 vs 누설하다

Use '누설하다' specifically for spoken secrets or confidential information.

유출하다 vs 방출하다

Use '방출하다' for the release of energy, light, or intentional release of resources.

Idioms & Expressions

"밑 빠진 독에 물 붓기"

— Pouring water into a bottomless pot. Describes an endless drain of resources.

그 사업은 밑 빠진 독에 물 붓기라 자본을 계속 유출하고 있다.

Informal/Idiomatic

"입이 가볍다"

— To have a light mouth (unable to keep secrets). Often leads to '누설' or '유출'.

그는 입이 가벼워 비밀을 유출하기 쉽다.

Informal

"발 없는 말이 천 리 간다"

— Words without feet travel a thousand li. News/leaks spread fast.

한 번 유출한 정보는 발 없는 말처럼 퍼진다.

Proverb

"소 잃고 외양간 고친다"

— Mending the barn after losing the cow. Taking security measures after a leak.

유출한 뒤에 보안을 강화하는 것은 소 잃고 외양간 고치는 격이다.

Proverb

"꼬리가 길면 밟힌다"

— If your tail is long, it will be stepped on. If you keep leaking things, you'll get caught.

계속 정보를 유출하다가 결국 꼬리가 밟혔다.

Proverb

"눈 가리고 아웅"

— Hiding your eyes and saying 'meow'. Trying to hide a leak with a shallow excuse.

기름을 유출하고도 모른 척하는 것은 눈 가리고 아웅이다.

Proverb

"낮 말은 새가 듣고 밤 말은 쥐가 듣는다"

— Birds hear the day talk, mice hear the night talk. Be careful of leaks.

낮 말은 새가 들으니 기밀을 유출하지 않도록 조심해라.

Proverb

"도둑이 제 발 저리다"

— A thief's feet go numb (guilt). A person who leaked info acting suspicious.

정보를 유출한 범인이 도둑 제 발 저리듯 행동했다.

Proverb

"가랑비에 옷 젖는 줄 모른다"

— Not realizing your clothes are getting wet in a drizzle. Small leaks adding up.

조금씩 유출하는 정보가 큰 피해를 줄 수 있다.

Proverb

"불난 데 부채질하다"

— Fanning the fire. Making a leak situation worse by spreading it.

유출한 정보를 유포하는 것은 불난 데 부채질하는 것이다.

Proverb

Easily Confused

유출하다 vs 배출하다

Both involve things going out.

배출하다 is usually for waste discharge or producing graduates; 유출하다 is for unauthorized leaks.

쓰레기를 배출하다 vs 정보를 유출하다.

유출하다 vs 추출하다

Both have '출' (exit).

추출하다 means 'to extract' (like coffee or data samples), not 'to leak'.

성분을 추출하다.

유출하다 vs 수출하다

Both involve 'flow out'.

수출하다 is 'to export' goods to another country commercially.

자동차를 수출하다.

유출하다 vs 탈출하다

Both involve 'exit'.

탈출하다 is 'to escape' (a place or a situation).

감옥에서 탈출하다.

유출하다 vs 노출하다

Both involve something becoming known.

노출하다 means 'to expose' or 'reveal' (like skin or a weakness).

피부를 노출하다.

Sentence Patterns

누가 [Object]를 유출했어요?

누가 비밀번호를 유출했어요?

[Object]를 유출하면 안 됩니다.

기밀을 유출하면 안 됩니다.

[Object]가 유출되었다는 소식을 들었어요.

정보가 유출되었다는 소식을 들었어요.

[Subject]은/는 [Object]를 유출한 혐의를 받고 있다.

그는 기술을 유출한 혐의를 받고 있다.

[Object] 유출로 인해 [Result]이/가 발생했다.

기름 유출로 인해 환경 오염이 발생했다.

[Object] 유출을 방지하기 위한 대책이 시급하다.

인재 유출을 방지하기 위한 대책이 시급하다.

고의적으로 [Object]를 유출했을 가능성이 크다.

고의적으로 정보를 유출했을 가능성이 크다.

[Object] 유출은 국가 경쟁력에 치명적인 손실을 초래한다.

기술 유출은 국가 경쟁력에 치명적인 손실을 초래한다.

Word Family

Nouns

유출 (leak/outflow)

유출자 (leaker)

유출물 (leaked material)

유출 사고 (leak accident)

Verbs

유출되다 (to be leaked - passive)

유출시키다 (to cause to leak)

Adjectives

유출된 (leaked - participial adjective)

수출 (export)

수입 (import)

유입 (inflow)

방출 (emission)

누출 (leakage)

How to Use It

frequency

High in news/media, Medium in daily life.

Common Mistakes

물이 유출해요 (for a small spill) → 물이 새요
유출하다 is too formal and large-scale for a small water spill.
정보가 유출했다 → 정보가 유출되었다
Information is the object, so it should be in the passive form '유출되다'.
비밀을 유출했어요 (to a friend) → 비밀을 누설했어요 / 말했어요
유출하다 sounds like a corporate crime; use 누설하다 for personal secrets.
가스를 유출됐어요 → 가스가 유출됐어요
With the passive '유출됐다', use the subject particle '가/이', not the object particle '를/을'.
영화 스포를 유출하다 → 영화 스포를 하다 / 누설하다
Spoilers are social, not usually described as '유출' unless it's a stolen script.

Tips

Check the Object

Always ensure you have an object with ~을/를 when using 유출하다. If there is no one doing the action, use 유출되다.

Hanja Power

Remember 流 (flow) and 出 (out). This helps you remember that 유출 is an 'out-flow'.

Professionalism

Use this word in business meetings or formal writing to sound more professional than using '새다'.

News Keywords

When you hear '유출', pay attention to the word before it (정보, 기름, 기술) to know what the news is about.

Legal Nuance

In legal contexts, '유출' often implies 'unauthorized release'. Use it when describing crimes.

Pronunciation

Don't rush the 'chul' sound. A clear 'ch' makes you sound much more like a native speaker.

Tech Sensitivity

Koreans are very sensitive about data leaks. Using this word shows you understand the gravity of the situation.

Visualizing Spills

Visualize a giant oil tanker leaking into the ocean. That scale of 'leak' is what '유출하다' feels like.

Scale Matters

Small leak = 새다. Big/Serious leak = 유출하다. This is the golden rule.

Proverb Link

Associate '유출' with '소 잃고 외양간 고친다' because security often comes after a leak.

Memorize It

Mnemonic

Imagine a 'U' (You) are 'Chul'ing (Chilling) and suddenly you fall 'Out' (Chul/Exit). You leaked out!

Visual Association

Imagine a pipe with a big 'U' shape and water 'Chul-ing' (flowing) out of a hole in the bottom.

Word Web

Flow Out Leak Data Oil Secret Hacker Exit

Challenge

Try to find three news articles today that use the word '유출'. You will likely find one about data and one about politics.

Word Origin

From Sino-Korean characters: 流 (유) meaning 'to flow' or 'stream' and 出 (출) meaning 'to go out' or 'exit'.

Original meaning: To flow out from a source.

Sino-Korean (Hanja-based)

Cultural Context

Avoid using this word for lighthearted secrets among friends; it can sound accusatory or overly dramatic.

English speakers often use 'leak' for both small things (faucet) and big things (NSA). In Korean, '유출하다' is strictly for the big/formal things.

The 'Hebei Spirit' Oil Spill (태안 기름 유출 사고) The 'Snowden' leaks (스노든의 기밀 유출) Samsung Semiconductor technology leak cases

Practice in Real Life

Real-World Contexts

Cybersecurity

데이터 유출
해킹으로 인한 유출
비밀번호 유출
보안 취약점

Environment

원유 유출
화학 물질 유출
방사능 유출
해양 오염

Business

영업 비밀 유출
기술 유출 방지
내부자 소행
경쟁사 유출

Economics

외화 유출
자본 유출 심화
국부 유출 논란
시장 불안

Education

시험지 유출
정답 유출
부정 행위
재시험 결정

Conversation Starters

"최근에 발생한 데이터 유출 사고에 대해 들어보셨나요?"

"기업들이 기술 유출을 막기 위해 어떤 노력을 해야 할까요?"

"기름 유출 사고가 환경에 미치는 영향은 무엇일까요?"

"개인정보가 유출되었을 때 가장 먼저 해야 할 일은 무엇입니까?"

"인재 유출 문제를 해결하기 위한 좋은 방법이 있을까요?"

Journal Prompts

만약 나의 개인정보가 온라인에 유출된다면 어떤 기분이 들지 써보세요.

기업의 기술 유출이 국가 경제에 미치는 영향에 대해 자신의 생각을 정리해보세요.

환경 보호를 위해 기업이 유해 물질을 유출하지 않도록 감시하는 방법에 대해 제안해보세요.

뉴스를 통해 본 가장 기억에 남는 유출 사고는 무엇인지 설명해보세요.

정보가 너무 쉽게 유출되는 현대 사회의 문제점과 해결책을 논해보세요.

Frequently Asked Questions

10 questions

No, that would sound very strange. For a faucet, use '물이 새다' (water is leaking). '유출하다' is for large-scale or high-stakes leaks like oil spills or data breaches.

'누설하다' is specifically for secrets and spoken information. '유출하다' is more general and can include physical substances (oil, water), digital data, and resources (money, people).

Almost always. It implies that something that should have been kept inside has escaped, usually leading to negative consequences like loss of money, privacy, or environmental damage.

You should use the passive form: '정보가 유출되었다'. Use '유출하다' when you want to specify who did the leaking (e.g., '해커가 정보를 유출했다').

No, '스포하다' is the common word for movie spoilers. '유출하다' would sound like the movie script was stolen from the studio.

It means 'brain drain'—when highly skilled or talented people leave their home country to work elsewhere.

Yes, '유출' is the noun form. You will often see it in compound nouns like '정보 유출' (information leak).

Yes, '가스 유출' is a common and correct term for a gas leak, especially in a technical or news context.

The most direct opposite is '유입하다' (to flow in). For information, '수집하다' (to collect) or '보호하다' (to protect) are also opposites in context.

Only when talking about the news or serious work issues. It's not a word you'd use for trivial daily accidents.