25 Expressions Related to Secrets

25 Expressions Related to Secrets (with Meanings & Examples)

25 Expressions Related to Secrets

Hello, dear English learners! Welcome to a brand-new lesson from My Lingua Academy. Today, we’re diving into one of the most intriguing corners of English vocabulary — 25 expressions related to secrets.

We all keep secrets from time to time. Some are lovely — like planning a surprise birthday party — and some are heavier, such as something embarrassing from the past. English has dozens of colourful idioms to help you talk about hiding, revealing, or discovering secrets.

Let’s explore 25 essential expressions, complete with clear meanings and natural example sentences.

A dark secret

A shameful or painful secret that someone wants to hide.

• John had an illegitimate child, and it remained a dark secret in the family for years.
• Fiona carried a dark secret that often kept her awake at night.

Hold your tongue

To stop yourself from saying something — especially something that should stay secret.

• While he was in the gang, Adam learned to hold his tongue about their activities.
• Hold your tongue! Don’t say a word about the surprise.

Keep/reveal a secret

Keep a secret = hide the information.

Reveal a secret = make it known.

• Can I trust you to keep a secret? Please don’t tell Rob that you’ve seen me.
• The scientists are trying to reveal the secret of the queen’s youthful appearance.

Like a thief in the night

To do something secretly and unexpectedly.

• Brian slipped out of the house like a thief in the night to meet his friends.
• The crisis struck the country like a thief in the night.

Make a secret of something / make no secret of something

To make a secret of something = try to hide it.

To make no secret of something = be open about it.

• The Smiths made a secret of their lottery win.
• The government made no secret of its plan to raise taxes. 

Mum’s the word

A friendly way of saying keep quiet, don’t tell anyone.

• I’m planning a surprise trip for my wife — mum’s the word!
• “Don’t tell Emma I used her laptop.” “Mum’s the word!”

My lips are sealed

A promise that you will not repeat someone’s secret.

• “Please don’t tell anyone.” “My lips are sealed.”
• I’d love to share more, but my lips are sealed.

Off the record

Information that must not be published or shared officially.

• The minister insisted his comment was off the record.
• This meeting is off the record — no recording is allowed.

On the sly

To do something secretly, often because it’s wrong or forbidden.

• They smuggled the goods out of the country on the sly.
• Simon had been seeing Helen on the sly for months.

A skeleton in the closet

A shameful or embarrassing secret from someone’s past.

• Peter’s grandfather committed a crime — their family skeleton in the closet.
• During the investigation, the skeleton in the closet finally came out.

Spill the beans

To reveal a secret, often accidentally. 

• We planned a surprise party, but someone spilt the beans.
• The robber spilt the beans as soon as he was caught.

Sweep something under the rug

To hide a problem instead of facing it.

• The company tried to sweep the financial losses under the rug.
• The family attempted to sweep the scandal under the rug, but the media found out.

To swear someone to secrecy

To make someone promise not to reveal information.

• Everyone involved in the project was sworn to secrecy.
• Before telling her the truth, he swore Anna to secrecy.

Your secret is safe with me

A reassurance that you won’t tell anyone.

• “Please don’t share this.” “Your secret is safe with me.”
• Don’t worry — your secret is absolutely safe with me.

Behind closed doors

Something done privately, away from the public eye.

• The decision was made behind closed doors.
• Important negotiations happened behind closed doors.

 Hush-hush

Something kept extremely secret or confidential.

• The whole operation was very hush-hush.
• They’re working on a hush-hush government project.

Cloak-and-dagger

Mysterious, secretive behaviour, often connected with spying or intrigue.

• The meeting felt like something out of a cloak-and-dagger novel.
• The journalist uncovered a cloak-and-dagger plot.

Under the table

Done secretly, usually illegally (often related to money).

• He was paid under the table to avoid taxes.
• The company made under-the-table deals for years.

On the quiet / on the QT

To do something secretly or privately.

• They got married on the quiet.
• He left the company on the QT after a disagreement with the boss.

Keep something under wraps

To keep something completely hidden or unannounced.

• The new product is being kept under wraps until March.
• They kept their engagement under wraps for months.

Blow the whistle

To report secret wrongdoing, especially at work.

• An employee blew the whistle on the company’s illegal practices.
• She finally blew the whistle on the corruption.

Behind someone’s back

To do something secretly without someone’s knowledge — usually negative.

• Tom sold the car behind his wife’s back.
• Don’t make decisions behind my back.

Let the cat out of the bag

To accidentally reveal a secret.

• Jane let the cat out of the bag about the holiday plans.
• Don’t let the cat out of the bag! It’s a surprise.

Keep it to yourself

A direct and friendly way of saying “Don’t tell anyone.” 

• I’ll tell you something, but keep it to yourself.
• Keep it to yourself — I haven’t told my parents yet.

In the loop / out of the loop

To be in the loop – to know the secret information.

 To be out of the loop – not informed.

• Only the managers are in the loop about the new project.
• I feel completely out of the loop. What’s going on?

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