leak

American  

[leek] / lik /

noun

1. an unintended hole, crack, or the like, through which liquid, gas, light, etc., enters or escapes.

   a leak in the roof.

2. an act or instance of leaking.

3. any means of unintended entrance or escape.

4. Electricity. the loss of current from a conductor, usually resulting from poor insulation.

5. a disclosure of secret, especially official, information, as to the news media, by an unnamed source.

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verb (used without object)

1. to let a liquid, gas, light, etc., enter or escape, as through an unintended hole or crack.

   The boat leaks.

2. to pass in or out in this manner, as liquid, gas, or light.

   gas leaking from a pipe.

3. to become known unintentionally (usually followed byout ).

   The news leaked out.

4. to disclose secret, especially official, information anonymously, as to the news media.

   The official revealed that he had leaked to the press in the hope of saving his own reputation.

verb (used with object)

1. to let (liquid, gas, light, etc.) enter or escape.

   This camera leaks light.

2. to allow to become known, as information given out covertly.

   to leak the news of the ambassador's visit.

idioms

1. take a leak, to urinate.

leak British  

/ liːk /

noun

1. 1. a crack, hole, etc, that allows the accidental escape or entrance of fluid, light, etc

   2. such escaping or entering fluid, light, etc

2. to develop a leak

3. something resembling this in effect

   a leak in the defence system

4. the loss of current from an electrical conductor because of faulty insulation, etc

5. a disclosure, often intentional, of secret information

6. the act or an instance of leaking

7. a slang word for urination See urination

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verb

1. to enter or escape or allow to enter or escape through a crack, hole, etc

2. to disclose (secret information), often intentionally, or (of secret information) to be disclosed

3. (intr) a slang word for urinate

Other Word Forms

• leaker noun
• leakless adjective
• nonleaking adjective

Etymology

Origin of leak

1375–1425; 1955–60 leak for def. 11; late Middle English leken < Old Norse leka to drip, leak; akin to Dutch lek, obsolete German lech leaky. See leach ¹

Explanation

A leak involves the release of something. It can be a behind-someone’s-back leak of sensitive information, a leak from a milk carton, or a leak in the roof that lets rain water drip in. As a verb, leak means to allow light or fluid to escape, or to enter or escape as though through a hole. Light can leak in through the curtains, water can leak out of an almost-closed faucet, or information can leak to the press. A leak is almost always a bad thing — it indicates that something that should be contained has broken out or escaped.

Example Sentences

Sixteen years after The Social Network, which depicted the birth of Facebook, a sequel will explore the 2021 Facebook leak by whistleblower Frances Haugen.

From BBC • Apr. 17, 2026

But the leak did reveal commercially sensitive information, including Anthropic’s proprietary techniques, tools and instructions for cajoling its AI models to work as coding agents.

From The Wall Street Journal • Apr. 1, 2026

The leak is a blow for Anthropic because it risks both undermining its reputation for safety and also revealing valuable trade secrets in the pitched battle for enterprise customers.

From The Wall Street Journal • Apr. 1, 2026

As the Anthropic leak showed, AI creates more security problems than it solves.

From Barron's • Mar. 30, 2026

“Based on what little we know, Ren’s being questioned by the police right now. I don’t buy the gas leak story.”

From "Warcross" by Marie Lu

Related Words

• discharge
• disclose
• divulge
• escape
• ooze
• pass on
• reveal
• spill
• trickle