50 Idioms for Secrets (Meanings & Examples)

Idioms are fun phrases that mean something different from the words inside them. People use them to make their speaking and writing more colorful and exciting. In this lesson, you will learn fifty special idioms related to keeping quiet, hidden stories, and secrets.

In this lesson, we’ll look at idioms that mean keeping information under wraps or letting something slip out. Let’s get started and explore some of these helpful expressions.

Idioms for Secrets

1. Under wraps

Definition: Kept secret, hidden, or protected from public knowledge until the right time.

Used in a Sentence: The surprise party plans were kept strictly under wraps so nobody would guess. / The movie studio kept the ending of the film under wraps.

Similar Expressions: Kept secret / Hidden away

2. Skeleton in the closet

Definition: A shameful or embarrassing secret from the past that someone wants to keep hidden.

Used in a Sentence: Every old house has its quirks, just like every family has a secret skeleton in the closet. / He worried that a past mistake would become a skeleton in the closet.

Similar Expressions: Hidden secret / Past shame

3. Let the cat out of the bag

Definition: To accidentally reveal a secret that was supposed to stay hidden.

Used in a Sentence: Mia accidentally let the cat out of the bag about the surprise birthday party. / Try not to let the cat out of the bag before the gift is opened.

Similar Expressions: Reveal secret / Give away surprise

4. Hush-hush

Definition: Extremely secret, confidential, and whispered about quietly.

Used in a Sentence: The club members held a hush-hush meeting behind closed doors. / The new invention project was kept very hush-hush at the office.

Similar Expressions: Highly confidential / Very secret

5. Keep it under your hat

Definition: To promise to keep a piece of information a secret and tell no one else.

Used in a Sentence: I am telling you this secret plan, but you must keep it under your hat. / He promised to keep the birthday gift idea under his hat.

Similar Expressions: Keep secret / Don’t tell

6. Spill the beans

Definition: To reveal a secret, often by accident or under pressure.

Used in a Sentence: After asking too many questions, the little boy finally spilled the beans about the puppy. / Who went ahead and spilled the beans about our plan?

Similar Expressions: Tell secret / Blab

7. A dark horse

Definition: Someone who keeps their hidden talents or secrets quiet until they surprise everyone.

Used in a Sentence: Leo turned out to be a dark horse in the chess tournament by winning every match. / Nobody expected her to win the art contest because she was a dark horse.

Similar Expressions: Quiet competitor / Hidden talent

8. Off the record

Definition: Information given informally that is not meant to be published or repeated publicly.

Used in a Sentence: The mayor shared some thoughts with reporters off the record before the meeting. / Speaking off the record, the coach admitted the game would be tough.

Similar Expressions: Informal chat / Not for public

9. Behind closed doors

Definition: Happening in private, away from the public view or outside listeners.

Used in a Sentence: The committee made their final decision behind closed doors. / Important team strategies were discussed behind closed doors.

Similar Expressions: In private / Secretly done

10. A closed book

Definition: A subject, person, or secret that is completely mysterious and hard to understand.

Used in a Sentence: Advanced calculus remained a closed book to me until the tutor explained it. / His past life before moving to our town was a total closed book.

Similar Expressions: Complete mystery / Unknown subject

11. Read between the lines

Definition: To understand a hidden meaning or secret message that isn’t spoken directly.

Used in a Sentence: When mom said she was fine with a tired voice, we had to read between the lines. / Reading between the lines of the letter revealed his true feelings.

Similar Expressions: Find hidden meaning / Perceive subtly

12. Loose lips sink ships

Definition: A warning phrase meaning that careless talking or sharing secrets can cause disaster.

Used in a Sentence: Remember to keep quiet about the surprise plan because loose lips sink ships. / Guard your words carefully during the project because loose lips sink ships.

Similar Expressions: Careless talk hurts / Keep secrets safe

13. Drop a hint

Definition: To give a small, subtle clue about a secret without giving everything away.

Used in a Sentence: She decided to drop a hint about what she wanted for her birthday. / The teacher dropped a hint about the upcoming test questions.

Similar Expressions: Give clue / Suggest subtly

14. Keep mum

Definition: To remain completely silent and refuse to speak about a secret.

Used in a Sentence: The witness promised to keep mum about what happened in the hallway. / Mom told us to keep mum until the cake was frosted.

Similar Expressions: Stay silent / Keep quiet

15. A trade secret

Definition: A confidential method, formula, or practice kept hidden by a business.

Used in a Sentence: The exact spice blend used in grandma’s soup recipe remained a strict trade secret. / Software companies protect their code like a valuable trade secret.

Similar Expressions: Business secret / Proprietary method

16. Guarded secret

Definition: Information protected carefully with high security and privacy.

Used in a Sentence: The combination to the safe was a tightly guarded secret. / Where the treasure map was hidden remained a guarded secret.

Similar Expressions: Protected knowledge / Hidden fact

17. In strict confidence

Definition: Sharing information with the strict agreement that it will never be repeated.

Used in a Sentence: He told me his worries in strict confidence, so I kept them to myself. / Please treat this report in strict confidence.

Similar Expressions: Privately / Confidentially

18. Open secret

Definition: Something that is supposed to be a secret, but everyone already knows about it.

Used in a Sentence: Everyone knew about the surprise party, making it an open secret in the house. / His plan to change jobs was an open secret among coworkers.

Similar Expressions: Known secret / Publicly known fact

19. Play your cards close to your chest

Definition: To keep your plans, intentions, or secrets hidden from other people.

Used in a Sentence: During the game negotiation, he played his cards close to his chest. / Successful inventors play their cards close to their chests before launching products.

Similar Expressions: Be secretive / Hide plans

20. Lock up and leave

Definition: A metaphorical way of securing secrets so they cannot escape.

Used in a Sentence: After discussing the sensitive topic, they decided to lock up and leave details unsaid. / Secure the documents and lock up and leave the room.

Similar Expressions: Secure information / Hide away

21. A dark secret

Definition: A very serious, hidden piece of information or past wrongdoing.

Used in a Sentence: In the mystery novel, the old mansion held a dark secret in the basement. / He carried a dark secret about who broke the window for days.

Similar Expressions: Deep secret / Grave mystery

22. Bury the past

Definition: To leave old secrets, mistakes, and troubles forgotten forever.

Used in a Sentence: After talking things out, the friends decided to bury the past and move forward. / It is often better to bury the past than hold onto old grudges.

Similar Expressions: Forget old wrongs / Let go of history

23. Behind someone’s back

Definition: Doing something, gossiping, or sharing secrets where a person cannot see or hear.

Used in a Sentence: It is unkind to talk about others behind their backs. / They planned the surprise party behind his back.

Similar Expressions: In private / Secretly

24. A nod is as good as a wink

Definition: A subtle gesture or hint used to communicate a secret understanding between people.

Used in a Sentence: They shared a quiet look because a nod is as good as a wink when you share a joke. / We didn’t need to speak; a nod is as good as a wink.

Similar Expressions: Subtle hint / Mutual understanding

25. Cover your tracks

Definition: To hide evidence, actions, or clues so nobody discovers what you did.

Used in a Sentence: The puppy tried to cover its tracks after knocking over the pillow. / Smart detectives look for clues where suspects try to cover their tracks.

Similar Expressions: Hide evidence / Erase clues

26. Sweep under the rug

Definition: To hide an embarrassing problem or secret so people forget about it.

Used in a Sentence: You cannot just sweep your mistakes under the rug; you must fix them. / The committee tried to sweep the budget error under the rug.

Similar Expressions: Hide problem / Ignore issue

27. On the QT (Quiet)

Definition: Doing something quietly, secretly, and without attracting notice.

Used in a Sentence: They planned the charity donation entirely on the QT. / Keep this project on the QT until the official announcement.

Similar Expressions: Secretly / Quietly done

28. Whisper campaigns

Definition: Spreading rumors or secret information quietly behind the scenes.

Used in a Sentence: The school election faced minor whisper campaigns in the hallways. / Whispering campaigns rarely lead to honest discussions.

Similar Expressions: Rumor spreading / Secret gossip

29. Keep in the dark

Definition: To intentionally prevent someone from knowing a secret or current news.

Used in a Sentence: Parents kept us in the dark about the vacation destination until we arrived at the airport. / Do not leave your team members in the dark about the schedule.

Similar Expressions: Keep uninformed / Hide details

30. Blow the whistle

Definition: To reveal a secret wrongdoing, illegal act, or scam to authorities.

Used in a Sentence: The employee decided to blow the whistle on the company’s bad accounting practices. / Whistleblowers help expose hidden corporate corruption.

Similar Expressions: Expose wrongdoing / Reveal secret

31. Let slip

Definition: To accidentally say a secret word or detail without meaning to.

Used in a Sentence: He let slip that we were having pizza for dinner. / Try not to let slip any details about the test.

Similar Expressions: Slip up / Reveal accidentally

32. Keep a lid on it

Definition: To keep a situation or secret under tight control and prevent it from spreading.

Used in a Sentence: The manager told everyone to keep a lid on the news until corporate approved it. / We need to keep a lid on our excitement during class.

Similar Expressions: Keep quiet / Restrain information

33. Talk in riddles

Definition: To speak in a confusing, mysterious way that conceals your true meaning.

Used in a Sentence: The old wizard always talked in riddles when asked about hidden treasure. / Stop talking in riddles and tell us the straight answer.

Similar Expressions: Speak mysteriously / Hide meaning

34. Smoke and mirrors

Definition: A deceptive, secretive trick designed to confuse people or hide the truth.

Used in a Sentence: The complex explanation turned out to be just smoke and mirrors. / Magic tricks rely on smoke and mirrors to amaze audiences.

Similar Expressions: Illusion / Deceptive trick

35. Pull the wool over someone’s eyes

Definition: To deceive someone or hide the truth from them with a trick.

Used in a Sentence: You cannot pull the wool over the teacher’s eyes with fake homework excuses. / The clever magician tried to pull the wool over our eyes.

Similar Expressions: Deceive / Fool someone

36. Behind the scenes

Definition: Hidden activities and secret work happening away from the public view.

Used in a Sentence: Working behind the scenes, stage crew members built amazing props for the play. / A lot of planning happens behind the scenes before a school concert.

Similar Expressions: Private work / Unseen preparation

37. Keep someone guessing

Definition: To withhold information or secrets so people stay curious about your plans.

Used in a Sentence: The mystery author loved to keep readers guessing until the very last page. / She kept her costume a secret to keep everyone guessing.

Similar Expressions: Stay mysterious / Withhold clues

38. Mum’s the word

Definition: A phrase telling someone to remain silent and promise not to tell a secret.

Used in a Sentence: I am planning a surprise visit, so mum’s the word to everyone. / Remember, mum’s the word regarding the test answers.

Similar Expressions: Keep quiet / Say nothing

39. Play possum

Definition: To pretend to be asleep, ignorant, or unaware to hide your true knowledge.

Used in a Sentence: The clever cat played possum on the rug until the mouse walked closer. / When asked about the broken vase, he played possum.

SimilarExpressions: Pretend ignorance / Act unaware

40. Keep your own counsel

Definition: To keep your thoughts, plans, and secrets entirely to yourself without sharing.

Used in a Sentence: Wise leaders often keep their own counsel before making big decisions. / She preferred to keep her own counsel during group arguments.

Similar Expressions: Stay private / Keep thoughts secret

41. A hidden agenda

Definition: A secret, unstated motivation or plan behind someone’s public actions.

Used in a Sentence: Voters grew suspicious when they suspected the politician had a hidden agenda. / Always watch out for salespeople with a hidden agenda.

Similar Expressions: Secret motive / Unstated plan

42. Cryptic message

Definition: A hidden, mysterious message that is difficult to decode or understand.

Used in a Sentence: The treasure hunter received a cryptic message written in ancient symbols. / Her note left a cryptic message about meeting after class.

Similar Expressions: Mysterious note / Secret code

43. Safe as houses

Definition: A secret or plan that is completely secure and protected from discovery.

Used in a Sentence: Put the documents in the locked drawer; they will be safe as houses. / Our secret hiding spot is safe as houses.

Similar Expressions: Totally secure / Well protected

44. Under the table

Definition: Secret, illicit, or hidden financial payments or business dealings.

Used in a Sentence: Honest companies never engage in under the table deals. / The shady agreement was made entirely under the table.

Similar Expressions: Secretly done / Illegal deal

45. Straight from the horse’s mouth

Definition: Hearing a secret or fact directly from the primary, most reliable source.

Used in a Sentence: I heard the news about the school trip straight from the horse’s mouth. / Get the project guidelines straight from the horse’s mouth.

Similar Expressions: Direct source / Reliable information

46. Behind the curtain

Definition: Hidden away from the audience in a private, secret preparation space.

Used in a Sentence: Actors waited nervously behind the curtain before the show started. / Looking behind the curtain revealed how the stage magic worked.

Similar Expressions: Backstage / Out of view

47. Cover story

Definition: A false explanation or secret excuse used to hide what really happened.

Used in a Sentence: The spies invented a cover story about traveling for business. / He needed a believable cover story for why he missed practice.

Similar Expressions: False excuse / Fabricated tale

48. Put in the dark

Definition: To keep someone completely unaware of a secret plan or change.

Used in a Sentence: We felt frustrated being put in the dark about the schedule changes. / Never leave your family put in the dark during emergencies.

Similar Expressions: Uninformed / Left unaware

49. Keep quiet

Definition: To refrain from speaking and guard a secret carefully.

Used in a Sentence: Please keep quiet about the prize winner until the assembly. / The children tried to keep quiet while hiding in the fort.

Similar Expressions: Stay silent / Hush up

50. Silent as the grave

Definition: Remaining completely quiet and refusing to ever reveal a secret.

Used in a Sentence: When asked about the surprise, he promised to be silent as the grave. / The old vault kept its contents hidden, silent as the grave.

Similar Expressions: Completely silent / Never telling

Exercise to Practice

1. The surprise party plans were kept strictly under wraps so nobody would guess.
2. Every old house has its quirks, just like every family has a secret skeleton in the closet.
3. Mia accidentally let the cat out of the bag about the surprise birthday party.
4. The club members held a very loud and public meeting in the center of town.
5. I am telling you this secret plan, but you must keep it under your hat.
6. After asking too many questions, the little boy finally spilled the beans about the puppy.
7. Leo turned out to be a dark horse in the chess tournament by winning every match.
8. The mayor shared some thoughts with reporters off the record before the meeting.
9. The committee made their public decisions in front of thousands of cheering fans.
10. Advanced calculus remained a closed book to me until the tutor explained it.
11. When mom said she was fine with a tired voice, we had to read between the lines.
12. Remember to keep quiet about the surprise plan because loose lips sink ships.
13. She decided to drop a hint about what she wanted for her birthday.
14. The witness promised to keep mum about what happened in the hallway.
15. The exact spice blend used in grandma’s soup recipe was published in the local newspaper.

Answer Key

1. True
2. True
3. True
4. False
5. True
6. True
7. True
8. True
9. False
10. True
11. True
12. True
13. True
14. True
15. False

Conclusion

Learning these idioms helps make your writing and speaking much more colorful and fun. Instead of using plain words, you can use these special expressions to describe hiding secrets, sharing clues, and keeping quiet. Try using one or two of these idioms when you talk to your friends or write a story today. Notice how much brighter and more interesting your conversations become.

Frequently Asked Questions

What are some common idioms for secrets?

Common idioms for secrets include keeping something under wraps, letting the cat out of the bag, and spilling the beans. These phrases help describe hidden information and classified plans in a colorful way.

Why do we use idioms in English?

We use idioms to make our language more expressive, creative, and interesting. They allow us to paint a picture with words instead of just stating simple facts.

How can I remember these idioms easily?

You can remember idioms by practicing them in daily conversations and writing your own funny sentences with them. Drawing pictures of what the literal words mean can also help you recall them.

Are idioms used in everyday spoken English?

Yes, native English speakers use idioms all the time in casual conversations, movies, books, and music. Learning them helps you understand what people mean when they talk or write.

Can I use these idioms in school writing?

You can use idioms in creative writing stories, journal entries, and speeches to make your writing stand out. Just remember to use formal language for serious reports and science papers.