Some secrets are harmless like planning a surprise party or hiding your little brother’s birthday gift in the closet. Others feel bigger, like when someone shares something private and says, “Don’t tell anyone.” In everyday American conversations, people talk about secrets without always saying the word “secret.” Instead, they use playful or serious phrases that paint a picture. These are called idioms about secrets, and they’re all over TV shows, books, and real-life chats.
Imagine your friend blurting out your surprise plans by accident. Someone might say, “Way to spill the beans.” Or when your teacher closes the door for a quiet talk, it’s happening behind closed doors. These idioms help people share secret situations in a fun, colorful way. Whether the secret is light, serious, or somewhere in between, these phrases help say it without saying too much.
Idioms About Secrets
1. Spill the beans
Meaning: To reveal a secret, especially by accident or too soon. People say this when someone gives away something that was supposed to be kept quiet.
Example Sentences:
• Sarah spilled the beans about the surprise party.
• He spilled the beans and told everyone about the plan.
• “Don’t spill the beans,” Mom warned before we got to Grandma’s house.
• In the meeting, John spilled the beans about the new store opening.
Other ways to say: Let it slip, tell the secret, blab
Fun Fact/Origin: This phrase comes from ancient Greece, where people voted using beans. If the beans were spilled, the results were revealed early.
Usage/Cultural Notes: This is a common and informal idiom in American English. Kids, teens, and adults all use it. It’s less common in British English, where “let the cat out of the bag” is more popular.
2. Let the cat out of the bag
Meaning: To accidentally share a secret that was supposed to be kept hidden. This usually happens when someone isn’t careful with their words.
Example Sentences:
• I let the cat out of the bag about her gift.
• He let the cat out of the bag before the party.
• “Oops, I think I let the cat out of the bag,” Jamie said after mentioning the promotion.
• The email let the cat out of the bag before the boss was ready.
Other ways to say: Slip up, reveal by mistake, blurt out
Fun Fact/Origin: This phrase comes from old markets where dishonest sellers would secretly put a cat in a bag instead of a pig. Once the cat was out, the trick was revealed.
Usage/Cultural Notes: Very common in both American and British English. Often used in casual speech, especially when someone ruins a surprise without meaning to.
3. Keep something under wraps
Meaning: To keep something hidden or secret, especially before it’s time to be shared. It’s used when people don’t want news or plans to get out early.
Example Sentences:
• We’re keeping the project under wraps.
• She kept the big news under wraps.
• The new phone design was kept under wraps until launch day.
• “Keep it under wraps until the meeting,” the manager said.
Other ways to say: Keep it quiet, don’t tell, keep it hush-hush
Fun Fact/Origin: “Wraps” used to mean cloth or covers used to hide items, like in a store or on stage.
Usage/Cultural Notes: This is used in American business, school, and media settings. It’s a bit more formal than “spill the beans” but still common in speech and writing.
4. In the know
Meaning: To be one of the people who has secret or special information. It means you’re part of a group that’s aware of what others don’t know.
Example Sentences:
• Only a few people are in the know.
• If you’re in the know, you understand what’s going on.
• She felt important being in the know about the school’s new rule.
• The staff who are in the know stayed late for a private meeting.
Other ways to say: Be informed, have the inside scoop, be clued in
Fun Fact/Origin: “In the know” first appeared in the early 1900s and has always meant having special knowledge or access.
Usage/Cultural Notes: Common in American English, especially in work, school, or news settings. “In the know” is sometimes replaced with “in on it” in informal conversations.
5. Skeleton in the closet
Meaning: A hidden secret from the past, often something embarrassing or shameful. It’s used when someone is hiding something they don’t want others to discover.
Example Sentences:
• Every family has a skeleton in the closet.
• He tried to hide his skeleton in the closet.
• “I hope that old story doesn’t come out—that’s a real skeleton in my closet,” she said.
• The candidate was popular until the media found his skeleton in the closet.
Other ways to say: Dark secret, hidden past, buried story
Fun Fact/Origin: The phrase likely comes from old stories where literal skeletons were hidden in closets to cover up crimes or bad deeds.
Usage/Cultural Notes: This idiom is used in both American and British English. It fits formal or dramatic situations, like news, politics, or family history. In Australia, “skeleton in the cupboard” is more common.
6. Hush-hush
Meaning: Something kept very quiet or private, usually on purpose. People say it when a plan or topic is meant to stay hidden from others.
Example Sentences:
• The project is hush-hush.
• They had a hush-hush meeting.
• That deal was so hush-hush, not even the staff knew.
• “It’s all hush-hush for now,” she whispered.
Other ways to say: Top secret, private, low-key
Fun Fact/Origin: The word “hush” is an old way of telling someone to be quiet—“hush-hush” just doubles the idea.
Usage/Cultural Notes: Common in American English, especially in work or government settings. British English sometimes uses “cloak and dagger” for very secret matters, though it’s a bit more dramatic.
7. Behind closed doors
Meaning: Something done in private where others can’t see or hear. It’s often used for meetings, decisions, or events that aren’t open to the public.
Example Sentences:
• The talks happened behind closed doors.
• All decisions were made behind closed doors.
• The deal was worked out behind closed doors.
• “We’ll discuss it behind closed doors,” said the coach.
Other ways to say: In private, secretly, out of sight
Fun Fact/Origin: The phrase refers to real closed doors that block sound or sight, keeping others from knowing what’s going on.
Usage/Cultural Notes: Common in American and British English, often used in politics, business, and family matters. It’s more formal than slang terms like “on the down low.”
8. Keep a lid on it
Meaning: To keep something from getting out or being talked about. It means you should stop the news or secrets from spreading.
Example Sentences:
• Keep a lid on the surprise.
• We need to keep a lid on the news.
• “Can you keep a lid on this?” Dad asked.
• The team kept a lid on the changes until launch day.
Other ways to say: Don’t tell anyone, keep quiet, zip it
Fun Fact/Origin: Just like putting a lid on a boiling pot keeps the steam in, this idiom means holding back information.
Usage/Cultural Notes: Very common in American English. Also used in Australian English, but British speakers often say “keep it under your hat” instead.
9. On the down low
Meaning: To do something privately and quietly, often because it’s sensitive or not for public knowledge. It’s casual and a bit sneaky.
Example Sentences:
• They’re dating on the down low.
• Let’s keep this on the down low.
• “Keep it on the DL,” said Mark.
• The sale was done on the down low, with no big ad.
Other ways to say: Quietly, secretly, under the radar
Fun Fact/Origin: This idiom comes from American slang, especially in urban culture, and is often shortened to “on the DL.”
Usage/Cultural Notes: Very common in American English, especially in casual speech. Less used in the UK, where “secretly” or “quietly” is more typical.
10. Keep it to yourself
Meaning: To not share something with anyone else. People say this when they trust someone to hold onto private or sensitive information.
Example Sentences:
• I’m telling you, but keep it to yourself.
• She kept it to herself even though it was big news.
• “Can you keep it to yourself?” Jake asked.
• He knew something important but kept it to himself.
Other ways to say: Stay silent, don’t share, don’t say a word
Fun Fact/Origin: This idiom means the secret should stay with you—like carrying it inside your head without letting it out.
Usage/Cultural Notes: Common across American, British, and Australian English. Works in casual and serious conversations, especially between friends or family.
11. Mum’s the word
Meaning: A way to say, “Don’t tell anyone.” It means total silence about the topic, even if someone asks.
Example Sentences:
• Mum’s the word about the surprise.
• He said, “Mum’s the word,” and walked away.
• “I promised to keep quiet—mum’s the word,” she said.
• They were told to keep quiet. Mum’s the word until the release.
Other ways to say: Stay quiet, don’t spill it, zip your lips
Fun Fact/Origin: “Mum” comes from an old English word that means silence—not related to the word for mother.
Usage/Cultural Notes: Still used in American and British English, though it sounds a little old-fashioned. It’s playful and often used in fun situations like surprises or birthday plans.
12. Sweep under the rug
Meaning: To hide a mistake or problem so no one sees it. It’s used when someone avoids dealing with something by pretending it didn’t happen.
Example Sentences:
• They tried to sweep the mistake under the rug.
• She swept the problem under the rug.
• The company swept the complaints under the rug.
• “Don’t sweep it under the rug,” Dad said. “We need to talk about it.”
Other ways to say: Hide it, pretend it didn’t happen, cover it up
Fun Fact/Origin: The phrase comes from the act of brushing dirt under a rug instead of cleaning it properly.
Usage/Cultural Notes: Common in American English for both personal and work issues. British English has a similar phrase: “brush it under the carpet.” Often used when something is hidden but might come out later.
13. Blow the whistle
Meaning: To report someone’s bad or secret behavior, especially when it breaks rules. This is usually about telling the truth even when others try to hide it.
Example Sentences:
• He blew the whistle on the cheating.
• She blew the whistle at work.
• The teacher blew the whistle on the stolen test answers.
• “If you blow the whistle, you could lose your job,” he warned.
Other ways to say: Expose, report, call out
Fun Fact/Origin: Comes from sports referees, who blow a whistle to stop play when someone breaks the rules.
Usage/Cultural Notes: Used in both American and British English, especially in business, schools, or sports. A “whistleblower” is someone who shares a serious secret, often about illegal or unsafe actions.
14. Keep it close to the vest
Meaning: To keep your ideas, feelings, or plans to yourself. It means you don’t tell others what you’re thinking until you’re ready.
Example Sentences:
• He kept the idea close to the vest.
• She plays things close to the vest.
• “He’s being quiet—definitely keeping it close to the vest,” said Lisa.
• The team kept their next move close to the vest.
Other ways to say: Keep it private, be secretive, stay quiet
Fun Fact/Origin: Comes from card games, where players hold their cards close so others can’t see. “Vest” is more American; British English says “close to the chest.”
Usage/Cultural Notes: Common in American English in business, sports, and casual talk. It shows caution or strategy. British speakers more often say “play it close to the chest.”
15. Under the table
Meaning: Something done in secret, often in a dishonest or unofficial way. It’s usually about money or deals that aren’t reported or allowed.
Example Sentences:
• He got paid under the table.
• They made the deal under the table.
• She was taking payments under the table.
• The bonus was handled under the table to avoid taxes.
Other ways to say: Secret deal, unofficial, off the books
Fun Fact/Origin: The phrase comes from doing something hidden—under the table—so others won’t notice.
Usage/Cultural Notes: Very common in American English when talking about off-the-record payments or shady actions. British English uses “cash in hand” for similar ideas.
16. Fly under the radar
Meaning: To stay unnoticed on purpose, especially when avoiding trouble or attention. It’s about doing something quietly so others don’t spot it.
Example Sentences:
• He flew under the radar all year.
• The plan flew under the radar until the last minute.
• She’s trying to fly under the radar at work.
• “Let’s keep this under the radar until we’re ready,” the coach said.
Other ways to say: Stay hidden, don’t draw attention, go unnoticed
Fun Fact/Origin: Comes from military planes flying low so they can’t be seen by radar.
Usage/Cultural Notes: Widely used in American English, especially in schools, offices, and pop culture. British speakers also use this, though slightly less often.
17. Seal your lips
Meaning: To stay silent and promise not to tell. It shows someone’s mouth is shut and the secret is safe.
Example Sentences:
• She sealed her lips and didn’t say a word.
• I sealed my lips after hearing the news.
• “Seal your lips, okay?” he said.
• The team sealed their lips about the new launch.
Other ways to say: Zip it, keep silent, lock your lips
Fun Fact/Origin: Comes from the idea of sealing something shut—like an envelope or a container—so nothing can get out.
Usage/Cultural Notes: Common in both American and British English. Used mostly in casual speech. A playful version of this is “zip your lips.”
18. A little bird told me
Meaning: Said when someone knows a secret but doesn’t want to name the person who told them. It’s a playful way to hide your source.
Example Sentences:
• A little bird told me it’s your birthday.
• “Who told you?” “A little bird.”
• “A little bird told me there’s a surprise waiting for you,” Mom said.
• He smiled and said, “Let’s just say a little bird told me.”
Other ways to say: I heard, Someone told me, Word got out
Fun Fact/Origin: Comes from old fairy tales and stories where birds carry messages or overhear people.
Usage/Cultural Notes: Common in American and British English. It’s light and fun, often used in friendly conversations or teasing moments.
19. Button your lip
Meaning: A strong way to tell someone to stop talking. It’s used when you want someone to stay quiet, especially about a secret.
Example Sentences:
• Button your lip before you ruin the surprise.
• He told me to button my lip about it.
• “You better button your lip,” she warned.
• The teacher told them to button their lips during the test.
Other ways to say: Be quiet, don’t speak, zip it
Fun Fact/Origin: The phrase comes from the image of sealing your mouth shut, like closing a shirt with a button.
Usage/Cultural Notes: Common in American English and sometimes in British English. It’s a bit old-school and can sound bossy or playful, depending on the tone.
20. Play it close to the chest
Meaning: To keep your thoughts or plans to yourself. It shows that someone is being careful and not sharing too much.
Example Sentences:
• She plays things close to the chest.
• He played it close to the chest and told no one.
• “You’re really playing it close to the chest,” her friend said.
• The company played their strategy close to the chest.
Other ways to say: Be private, don’t share, hold back
Fun Fact/Origin: This is another version of “close to the vest,” both from card games where players hide their cards near their chest so no one can see.
Usage/Cultural Notes: Used widely in American English. In the UK, people say “close to the chest” more than “vest,” but both mean the same thing. It’s often used in sports, business, or strategy talks.
21. Dead giveaway
Meaning: Something that clearly shows the truth or secret without needing to say anything. It’s often used when someone accidentally reveals a surprise.
Example Sentences:
• Her smile was a dead giveaway.
• The muddy shoes were a dead giveaway.
• That look on your face was a dead giveaway.
• The note left on the table was a dead giveaway.
Other ways to say: Obvious clue, clear sign, sure sign
Fun Fact/Origin: “Dead” here means “certain” or “sure”—like a “dead shot” or “dead center.”
Usage/Cultural Notes: Popular in American English for casual talk. It’s often used with humor when someone gives away something without meaning to.
22. Drop a hint
Meaning: To give a small clue or suggestion without saying something directly. It’s used when someone wants to share something quietly or test how someone reacts.
Example Sentences:
• He dropped a hint about the gift.
• She kept dropping hints all day.
• “I think she’s dropping a hint,” said Max.
• The teacher dropped a hint about a surprise quiz.
Other ways to say: Suggest, give a clue, point toward
Fun Fact/Origin: The word “hint” comes from older English and meant a light or gentle touch—like softly pointing at something.
Usage/Cultural Notes: Common in American, British, and Australian English. Often used in romantic, family, or classroom situations when someone’s trying not to be too direct.
23. In confidence
Meaning: Said or shared with trust that it will be kept private. It’s used when someone wants you to keep what they said secret.
Example Sentences:
• I told her in confidence.
• This stays in confidence.
• “I’m sharing this in confidence,” he said.
• The story was passed along in confidence.
Other ways to say: Secretly, privately, just between us
Fun Fact/Origin: The word “confidence” comes from Latin and means “to have full trust.”
Usage/Cultural Notes: Used in both American and British English. This phrase sounds more formal and is often used in work or serious talks.
24. Under the radar
Meaning: To stay unnoticed and out of sight. People use this to describe actions or events that go quietly without drawing attention.
Example Sentences:
• He stayed under the radar during the event.
• Their plan stayed under the radar.
• She flew under the radar all semester.
• The idea stayed under the radar until launch day.
Other ways to say: Low profile, unnoticed, quiet
Fun Fact/Origin: Comes from military aviation—planes that fly low to avoid radar detection can’t be seen on screens.
Usage/Cultural Notes: Common in American English and also used in British English. It’s often used to describe someone staying quiet to avoid trouble or keep plans hidden.
25. Inside scoop
Meaning: Secret or special information that most people don’t know. It’s used when someone has access to private or early details.
Example Sentences:
• She had the inside scoop on the project.
• Want the inside scoop? Ask Jake.
• He gave me the inside scoop about the new teacher.
• “I’ve got the inside scoop,” said Leah with a grin.
Other ways to say: Secret info, behind-the-scenes, inside info
Fun Fact/Origin: The word “scoop” comes from journalism. A “scoop” is a big story reported before anyone else.
Usage/Cultural Notes: Very common in American English, especially in media, gossip, and casual conversations. British English sometimes says “exclusive” instead.
26. Secret’s out
Meaning: The hidden thing is now known by others. It’s used when something that was private is no longer a secret.
Example Sentences:
• The secret’s out about the baby.
• Everyone knows—the secret’s out.
• “Well, the secret’s out now,” she said after the announcement.
• He tried to hide it, but the secret’s out.
Other ways to say: It’s known, word’s out, everyone knows
Fun Fact/Origin: It’s just a short, casual way to say a secret is no longer hidden.
Usage/Cultural Notes: This phrase is casual and often said with humor or surprise. Used in American and British English in everyday talk.
27. Read between the lines
Meaning: To understand the hidden or deeper meaning in what someone says. It’s used when someone picks up clues that aren’t directly said.
Example Sentences:
• I read between the lines and knew something was wrong.
• You have to read between the lines to get it.
• She didn’t say it, but I read between the lines.
• “If you read between the lines, you’ll see what he meant,” said the teacher.
Other ways to say: Guess, figure out, catch the hint
Fun Fact/Origin: This comes from the idea of secret or invisible writing placed between lines of text.
Usage/Cultural Notes: Used across American, British, and Australian English. Common in schools, literature, or emotional conversations where people don’t speak openly.
28. Keep something to your chest
Meaning: To keep something private or secret. It’s used when a person chooses not to share their thoughts or plans with others.
Example Sentences:
• He kept his plan to his chest.
• She’s keeping it close to her chest.
• They kept their ideas to their chest during the meeting.
• “You’re keeping that to your chest, huh?” said her friend.
Other ways to say: Be private, not tell, hold back
Fun Fact/Origin: Like “close to the vest,” this phrase comes from card games where players hide their cards close to their chest.
Usage/Cultural Notes: This form is less common in British English, where “close to the chest” or “close to the vest” is preferred. All mean the same thing and are used in business or personal planning.
29. The walls have ears
Meaning: Someone might be listening, even if you can’t see them. It’s a warning to be careful about what you say.
Example Sentences:
• Don’t talk here—the walls have ears.
• Whisper, the walls have ears.
• “Let’s save it for later,” he said. “The walls have ears.”
• She lowered her voice. “The walls have ears in this place.”
Other ways to say: Be careful, someone might hear, keep it quiet
Fun Fact/Origin: This phrase was used in castles and war rooms where secret listeners might hide behind walls.
Usage/Cultural Notes: Still used in American and British English, often in dramatic or serious talks. Sometimes used jokingly in families or schools.
30. Top secret
Meaning: Very private and not to be shared with anyone except those with permission. It means the highest level of secrecy.
Example Sentences:
• The mission was top secret.
• That’s top secret info.
• “It’s top secret,” he whispered.
• The files were marked as top secret.
Other ways to say: Very private, not to be shared, highly classified
Fun Fact/Origin: Often used in the military to mark documents or plans that are restricted to certain people.
Usage/Cultural Notes: Common in American English and used in both serious and fun ways. Kids use it in games, while governments use it in official records. British English uses the same term.
31. In on it
Meaning: To be part of a secret or hidden plan. It means someone was included in what was going on behind the scenes.
Example Sentences:
• Were you in on it?
• She was in on the surprise.
• “I can’t believe you were in on it too,” said Jake.
• Everyone was in on it except me.
Other ways to say: Included, part of the plan, involved
Fun Fact/Origin: The phrase comes from “on it,” which means being active or involved in something.
Usage/Cultural Notes: Common in American and British English. Often used in playful situations, like pranks, or in serious talks about hidden actions.
32. Zip your lips
Meaning: To stay quiet and not say anything. It’s a fun way to ask someone to keep a secret.
Example Sentences:
• Zip your lips about the party.
• He zipped his lips when asked.
• “Zip your lips,” Mom said with a smile.
• I zipped my lips like she told me.
Other ways to say: Stay silent, don’t speak, hush up
Fun Fact/Origin: This comes from imagining your lips being zipped shut like a zipper.
Usage/Cultural Notes: Common in American English and used playfully, especially with kids. In British English, people might say “keep schtum” (a borrowed word from German) instead.
33. Keep something in the dark
Meaning: To leave someone without important information. It means hiding the truth from someone who’s not supposed to know.
Example Sentences:
• They kept me in the dark about the plan.
• She was in the dark the whole time.
• “You were in the dark? That’s not fair,” said Ella.
• He kept his team in the dark until the big reveal.
Other ways to say: Hide info, leave out, not inform
Fun Fact/Origin: “Dark” here means the opposite of “light,” which stands for truth or knowledge.
Usage/Cultural Notes: Used in American, British, and Australian English. It’s common in work or family settings when someone feels left out.
34. Tight-lipped
Meaning: To stay quiet on purpose, especially when asked something. It’s often used when someone refuses to share a secret.
Example Sentences:
• He stayed tight-lipped all day.
• She was tight-lipped about the trip.
• The coach stayed tight-lipped before the big game.
• “Why are you so tight-lipped today?” asked his friend.
Other ways to say: Silent, not sharing, closed off
Fun Fact/Origin: A tight mouth is one that won’t open—so it’s used to show someone won’t speak.
Usage/Cultural Notes: Common in American and British English, especially in serious or news settings. Sometimes it sounds formal or secretive.
35. Break a confidence
Meaning: To tell something that someone asked you to keep private. It means losing someone’s trust by sharing their secret.
Example Sentences:
• She broke my confidence.
• He broke my confidence and told my secret.
• “You promised—don’t break my confidence,” said Mia.
• The article broke a confidence by naming the source.
Other ways to say: Betray trust, tell a private thing, spill a secret
Fun Fact/Origin: “Confidence” means trust in this case. Breaking it means breaking a promise to stay quiet.
Usage/Cultural Notes: This phrase is used in both American and British English, often in formal or serious situations. It’s about personal or professional trust.
Quiz: Idioms About Secrets
Instructions: Read each question and the answer choices carefully. Pick the letter that best matches the meaning of the phrase or expression.
Question Key
1. What does “spill the beans” mean?
A) Drop your lunch
B) Tell a secret
C) Cook dinner
2. If someone “lets the cat out of the bag,” what have they done?
A) Set an animal free
B) Hidden a toy
C) Revealed a secret
3. What does it mean to “keep something under wraps”?
A) Wrap a present
B) Keep something secret
C) Tie a rope
4. If you’re “in the know,” you:
A) Are guessing
B) Have secret information
C) Are lost
5. What does “skeleton in the closet” mean?
A) A Halloween decoration
B) An old secret someone hides
C) A toy in a box
6. If someone says “mum’s the word,” what should you do?
A) Talk to your mom
B) Stay quiet
C) Sing a song
7. What does it mean to “drop a hint”?
A) Give a clue
B) Drop something
C) Say nothing
8. If a person is “tight-lipped,” they:
A) Talk too much
B) Smile a lot
C) Say nothing
9. If you hear “the walls have ears,” what should you do?
A) Speak loudly
B) Stop talking
C) Look for ears
10. What happens if someone “breaks a confidence”?
A) They keep a promise
B) They share a private secret
C) They build trust
Answer Key
- B) Tell a secret
- C) Revealed a secret
- B) Keep something secret
- B) Have secret information
- B) An old secret someone hides
- B) Stay quiet
- A) Give a clue
- C) Say nothing
- B) Stop talking
- B) They share a private secret
Wrapping Up
Secrets are part of everyday life whether you’re planning a birthday party, keeping a surprise from a friend, or hearing something in private. In the USA, people often don’t say the word “secret” at all. Instead, they use clever idioms that paint a picture, like “spill the beans” or “keep it under wraps.” These phrases make talking about private things feel more fun and more natural.
Now that you’ve learned these idioms about secrets, try using them in your own conversations. They’ll help you sound more like a native speaker and add color to your everyday language. Just remember—sometimes it’s fun to drop a hint, but other times, it’s best to stay tight-lipped.
