Mystery is all around us. It can be a strange noise in the night, a secret to uncover, or a story that keeps us guessing. People in the USA love watching mystery movies, reading detective books, and solving puzzles. When something is hard to explain or understand, we call it a mystery. To describe these moments, people often use idioms. These are fun and clever phrases that help make language more exciting.
In this article, we’ll look at idioms about mystery. These phrases are used in everyday American conversations, especially when something is puzzling, secret, or unclear. You’ll find out what each one means, how people use it, and even where it came from. These idioms can help you sound more natural when speaking English, and they make talking about mystery more interesting. Let’s get started.
Idioms About Mystery
1. Skeleton in the closet
Meaning: A secret from the past that someone wants to hide
Example Sentence:
• Every family has a skeleton in the closet.
• That politician has a few skeletons in his closet.
Other ways to say: Hidden past, buried secret
Fun Fact/Origin: This phrase comes from the idea of hiding something scary, like a skeleton, in a closet so no one sees it.
Usage: Common in the USA when talking about private secrets someone doesn’t want revealed.
2. Spill the beans
Meaning: To reveal a secret or surprise
Example Sentence:
• Don’t spill the beans about the surprise party.
• He accidentally spilled the beans during dinner.
Other ways to say: Tell the secret, give it away
Fun Fact/Origin: It may come from an old voting method using beans, where spilling them revealed the result.
Usage: Often used when someone tells a secret too soon.
3. Behind closed doors
Meaning: Something done in private or secretly
Example Sentence:
• The deal was made behind closed doors.
• They made the decision behind closed doors.
Other ways to say: In secret, privately
Fun Fact/Origin: Comes from the image of doing something where no one can see or hear.
Usage: Used when talking about private meetings or actions.
4. Keep something under wraps
Meaning: To keep something secret
Example Sentence:
• We need to keep the plan under wraps.
• The new phone design is under wraps.
Other ways to say: Keep secret, hide
Fun Fact/Origin: “Wraps” refers to covering something, like wrapping a gift.
Usage: Often used for surprises or new ideas.
5. Blow the cover
Meaning: To reveal someone’s identity or a secret plan
Example Sentence:
• The article blew the cover on the scam.
• He accidentally blew her cover at the party.
Other ways to say: Expose, reveal
Fun Fact/Origin: Comes from spy language, where “cover” means hidden identity.
Usage: Common in stories about spying or secrets.
6. Under the radar
Meaning: Not noticed or detected
Example Sentence:
• He stayed under the radar to avoid attention.
• That idea flew under the radar.
Other ways to say: Go unnoticed, stay hidden
Fun Fact/Origin: Comes from flying low enough to avoid being seen by radar.
Usage: Used when someone or something avoids being noticed.
7. Red herring
Meaning: A clue meant to mislead
Example Sentence:
• The story had many red herrings.
• That clue was just a red herring.
Other ways to say: Distraction, false clue
Fun Fact/Origin: Comes from using a strong-smelling fish to throw off hunting dogs.
Usage: Common in mystery books and movies.
8. Smoke and mirrors
Meaning: Tricks used to hide the truth
Example Sentence:
• The report was all smoke and mirrors.
• He used smoke and mirrors to impress the crowd.
Other ways to say: Illusion, trickery
Fun Fact/Origin: Comes from magic shows that use smoke and mirrors for special effects.
Usage: Used when things aren’t what they seem.
9. In the dark
Meaning: Not knowing about something
Example Sentence:
• I was kept in the dark about the changes.
• She felt in the dark during the meeting.
Other ways to say: Unaware, clueless
Fun Fact/Origin: Darkness means you can’t see, just like not knowing something.
Usage: Common in everyday American speech.
10. Lift the veil
Meaning: To reveal the truth
Example Sentence:
• The movie lifts the veil on real life in space.
• The article lifted the veil on the company’s secrets.
Other ways to say: Uncover, reveal
Fun Fact/Origin: A veil covers the face, and lifting it shows what’s underneath.
Usage: Often used for revealing something hidden or unknown.
11. Secret sauce
Meaning: A special, hidden part that makes something successful
Example Sentence:
• Hard work is his secret sauce for success.
• Their secret sauce is great customer service.
Other ways to say: Special ingredient, hidden key
Fun Fact/Origin: Comes from recipes where a “secret sauce” makes food taste better.
Usage: Used in the USA to describe something special that makes a plan or product better.
12. Keep it close to the vest
Meaning: To keep something secret or not share much
Example Sentence:
• He kept his plans close to the vest.
• She always plays things close to the vest.
Other ways to say: Keep quiet, not reveal much
Fun Fact/Origin: Comes from card games where players hide their cards near their chest.
Usage: Used when someone avoids sharing ideas or feelings.
13. Cloak and dagger
Meaning: Secret, mysterious, or spy-like activity
Example Sentence:
• The story was full of cloak and dagger events.
• Their meeting felt like a cloak and dagger scene.
Other ways to say: Secret mission, spy work
Fun Fact/Origin: Refers to old spy stories where characters wore cloaks and carried daggers.
Usage: Often used to describe spy movies or secret plans.
14. Keep someone guessing
Meaning: To make things unclear on purpose
Example Sentence:
• She keeps us guessing about her next move.
• The show keeps the audience guessing.
Other ways to say: Be unpredictable, hide the truth
Fun Fact/Origin: Mystery shows use this to keep viewers interested.
Usage: Common in American entertainment and conversation.
15. Let the cat out of the bag
Meaning: To accidentally reveal a secret
Example Sentence:
• He let the cat out of the bag about the party.
• She let the cat out of the bag too early.
Other ways to say: Reveal a surprise, tell a secret
Fun Fact/Origin: May come from market scams where a cat was sold instead of a pig in a bag.
Usage: Used when someone slips and tells something they shouldn’t.
16. Mask the truth
Meaning: To hide or cover up the truth
Example Sentence:
• He masked the truth to avoid trouble.
• The smile masked how she really felt.
Other ways to say: Hide the truth, cover it up
Fun Fact/Origin: Comes from wearing a mask to hide the real face.
Usage: Often used when someone isn’t being honest.
17. Keep it under your hat
Meaning: Keep something a secret
Example Sentence:
• Keep this under your hat until Monday.
• He told me, but said to keep it under my hat.
Other ways to say: Don’t tell, keep quiet
Fun Fact/Origin: Old British saying from the 1800s.
Usage: Still used in the USA when asking someone to keep a secret.
18. Throw someone off the scent
Meaning: To mislead or confuse someone
Example Sentence:
• They used fake clues to throw the cops off the scent.
• He threw her off the scent by acting busy.
Other ways to say: Mislead, distract
Fun Fact/Origin: Comes from hunting, where scent dogs follow a trail.
Usage: Common when talking about tricks or plans.
19. Crack the code
Meaning: To solve a mystery or figure something out
Example Sentence:
• She cracked the code to the escape room.
• He finally cracked the code of the puzzle.
Other ways to say: Solve, figure out
Fun Fact/Origin: Comes from real code-breaking, especially during wartime.
Usage: Popular in tech, games, and schoolwork.
20. A closed book
Meaning: Something hard to understand or a person who is private
Example Sentence:
• That subject is a closed book to me.
• He’s a closed book—hard to know what he’s thinking.
Other ways to say: Mysterious, hard to read
Fun Fact/Origin: If a book is closed, you can’t read what’s inside.
Usage: Common in daily talk when someone is hard to understand.
21. Draw a blank
Meaning: To not remember or find something
Example Sentence:
• I drew a blank when trying to remember the name.
• He drew a blank on the test question.
Other ways to say: Forget, fail to recall
Fun Fact/Origin: Comes from lottery systems where a “blank” was a non-winning draw.
Usage: Used often in school and work.
22. Mind like a steel trap
Meaning: Very sharp memory or quick thinking
Example Sentence:
• She has a mind like a steel trap.
• He remembered everything—like a steel trap.
Other ways to say: Sharp mind, quick thinker
Fun Fact/Origin: Steel traps snap shut quickly—just like someone’s quick memory.
Usage: Used to describe someone who catches on fast or remembers well.
23. Cloud of suspicion
Meaning: When someone is suspected of doing something wrong
Example Sentence:
• He lived under a cloud of suspicion after the theft.
• There was a cloud of suspicion over the coach’s actions.
Other ways to say: Doubt, mistrust
Fun Fact/Origin: Clouds cover the sun, just like doubt covers trust.
Usage: Common in news and crime stories in the USA.
24. Out of the blue
Meaning: Something that happens unexpectedly
Example Sentence:
• She showed up out of the blue.
• The phone call came out of the blue.
Other ways to say: Unexpected, sudden
Fun Fact/Origin: Comes from the sky, where clear blue skies suddenly have storms.
Usage: Everyday use for surprise events.
25. Clam up
Meaning: To stop talking or refuse to speak
Example Sentence:
• He clammed up when the teacher asked him.
• She clammed up during the interview.
Other ways to say: Go silent, freeze up
Fun Fact/Origin: Clams close tightly, just like someone who won’t speak.
Usage: Often used when someone is nervous or hiding something.
26. Keep someone in suspense
Meaning: To delay giving information, keeping someone curious
Example Sentence:
• The show kept viewers in suspense until the end.
• Don’t keep me in suspense—just tell me.
Other ways to say: Delay, leave guessing
Fun Fact/Origin: From stories and movies that build tension.
Usage: Common in storytelling and entertainment.
27. Veil of secrecy
Meaning: A strong effort to keep something secret
Example Sentence:
• The project was under a veil of secrecy.
• There was a veil of secrecy over the case.
Other ways to say: Hidden, covered
Fun Fact/Origin: A veil covers things from view, just like secrecy hides facts.
Usage: Often used in politics and big projects.
28. Be tight-lipped
Meaning: To refuse to speak or share information
Example Sentence:
• The coach was tight-lipped about the lineup.
• She stayed tight-lipped during the meeting.
Other ways to say: Silent, closed
Fun Fact/Origin: Comes from holding your lips together so nothing escapes.
Usage: Used when someone chooses not to talk, often in serious situations.
Quiz: Idioms About Mystery
Instructions: Choose the correct meaning for each idiom. These questions will help you understand how mystery idioms are used in real-life situations. Pick the best answer from A, B, or C.
Question Key
1. What does “spill the beans” mean?
A) To clean up a mess
B) To tell a secret
C) To eat too much
2. If someone is “in the dark,” what does that mean?
A) They are outside at night
B) They don’t know what is happening
C) They forgot to turn on the light
3. What does “skeleton in the closet” mean?
A) A Halloween decoration
B) A joke someone tells often
C) A secret someone wants to keep hidden
4. When someone “clams up,” what are they doing?
A) Going to the beach
B) Talking a lot
C) Staying silent
5. If you “keep something under wraps,” what does it mean?
A) To wrap a present
B) To keep something secret
C) To put something in a box
6. What is a “red herring” used for?
A) To feed a pet
B) To tell a funny story
C) To distract someone from the truth
7. What does “let the cat out of the bag” mean?
A) To free an animal
B) To reveal a secret
C) To clean a room
8. If someone “goes under the radar,” what happens?
A) They get noticed by everyone
B) They are hard to see or find
C) They go on an airplane
9. What does “tight-lipped” mean?
A) Someone talks a lot
B) Someone eats quietly
C) Someone refuses to speak
10. If a person “keeps it close to the vest,” what are they doing?
A) Holding their jacket
B) Hiding their ideas or feelings
C) Cleaning their clothes
Answer Key
- B – To tell a secret
- B – They don’t know what is happening
- C – A secret someone wants to keep hidden
- C – Staying silent
- B – To keep something secret
- C – To distract someone from the truth
- B – To reveal a secret
- B – They are hard to see or find
- C – Someone refuses to speak
- B – Hiding their ideas or feelings
Wrapping Up
Mystery makes life more exciting. In the USA, people use many idioms to talk about secrets, surprises, and puzzling things. These idioms add fun and style to everyday conversations. Whether you’re watching a mystery movie or just trying to figure something out, these phrases help explain what’s going on.
By learning idioms like “under the radar” or “spill the beans,” you can better understand what others are saying. And you’ll sound more natural when you speak. Try using some of these mystery idioms next time you talk with friends or write a story. It will help make your words more interesting and clear.
