Idioms are special figurative expressions where the words together create a meaning completely different from what they say individually. People use them in everyday speech to describe dishonest, insincere, or untrustworthy individuals in a colorful and memorable way. In this article, you will learn fifty unique idioms related to a fake person.
In this lesson, we’ll look at idioms that mean insincere, two-faced, and untrustworthy behavior. Let’s get started and explore some of these helpful expressions.
Idioms for a Fake Person
1. Actor
Definition: A person who pretends to be someone they are not just to trick others.
Used in a Sentence: Don’t believe his sweet compliments because he is just an actor playing a part. / She proved she was a great actor when she hid her true feelings.
Similar Expressions: Pretender / Fraud
2. All talk and no trousers
Definition: Someone who makes big promises but never actually follows through on them.
Used in a Sentence: He promised to help build the entire stage set, but he is all talk and no trousers. / Don’t rely on his big claims because he is all talk and no trousers.
Similar Expressions: Braggart / Empty promise maker
3. Apple of discord
Definition: A deceitful person who intentionally stirs up trouble among friends.
Used in a Sentence: She loves spreading rumors and acts like an apple of discord in our club. / Keep away from that apple of discord if you want peace in the group.
Similar Expressions: Troublemaker / Instigator
4. Backstabber
Definition: A dishonest person who pretends to be your friend while secretly hurting you.
Used in a Sentence: Trusting him was a mistake because he turned out to be a total backstabber. / A true friend would never gossip behind your back like a backstabber.
Similar Expressions: Betrayer / Two-faced friend
5. Bad egg
Definition: An unreliable, dishonest, and untrustworthy individual.
Used in a Sentence: The store manager realized that applicant was a bad egg and didn’t hire him. / Stay away from that bad egg if you want to stay out of trouble.
Similar Expressions: Dishonest person / Troublemaker
6. Big talking machine
Definition: Someone who acts important and speaks grandly but lacks genuine substance.
Used in a Sentence: He claims he can win any game easily like a big talking machine, but he always loses. / Ignore his boastful words since he is just a big talking machine.
Similar Expressions: Braggart / Show-off
7. Chameleon
Definition: A person who constantly changes their personality and opinions to fit in with whoever is watching.
Used in a Sentence: She is such a chameleon that she agrees with whatever group she is standing near. / You never know what he really thinks because he acts like a chameleon.
Similar Expressions: Two-faced person / Shapeshifter
8. Cheap imitation
Definition: Someone who tries to copy someone else’s style or success in a fake way.
Used in a Sentence: His fake jokes and copied jokes make him look like a cheap imitation of a comedian. / Don’t try to be a cheap imitation of your older brother.
Similar Expressions: Copycat / Phony replica
9. Cloak and dagger
Definition: Describing a sneaky, secretive person who hides their true intentions.
Used in a Sentence: Why are you acting so cloak and dagger about where you bought those stickers? / His cloak and dagger behavior made everyone suspicious of his plans.
Similar Expressions: Sneaky person / Secretive individual
10. Con artist
Definition: A deceitful person who tricks others out of trust or items using lies.
Used in a Sentence: The card trickster turned out to be a smooth con artist trying to win our prizes. / Don’t fall for his clever tricks like a gullible victim of a con artist.
Similar Expressions: Swindler / Trickster
11. Copycat
Definition: Someone who insincerely copies your ideas or style while pretending they are original.
Used in a Sentence: She bought the exact same backpack and pretended she thought of it first, acting like a copycat. / Stop being a copycat and draw your own creative design.
Similar Expressions: Imitator / Unoriginal person
12. Cry crocodile tears
Definition: A person who pretends to be sad or caring when they actually do not care at all.
Used in a Sentence: He cried crocodile tears when he got caught breaking the rule, but he wasn’t sorry. / Don’t believe her fake crying because those are just crocodile tears.
Similar Expressions: Fake grief / Insincere sorrow
13. Double agent
Definition: Someone who pretends to be on your side while secretly working against you.
Used in a Sentence: We found out he was sharing our club secrets with the rival team like a double agent. / You can’t trust anyone who acts like a double agent during group games.
Similar Expressions: Traitor / Secret helper of rivals
14. Empty suit
Definition: A person in charge who looks important on the outside but has no genuine skill or character.
Used in a Sentence: The guest speaker had no helpful advice and turned out to be a total empty suit. / Don’t let fancy clothes fool you into thinking someone isn’t an empty suit.
Similar Expressions: Phony leader / Substance-free person
15. Fair-weather friend
Definition: A fake friend who only stays close when things are easy and disappears when trouble starts.
Used in a Sentence: When my bicycle broke down, he refused to help me, proving he was a fair-weather friend. / You find out who your real friends are when a fair-weather friend walks away.
Similar Expressions: Untrue companion / Unreliable friend
16. Fake smile
Definition: A forced, insincere facial expression used to hide true negative feelings.
Used in a Sentence: I could tell she didn’t like the gift because she wore a stiff, fake smile. / Behind his polite, fake smile, he was actually quite annoyed.
Similar Expressions: Forced grin / Insincere expression
17. False alarm
Definition: A person who acts like they are trustworthy or exciting but turns out to be a disappointment.
Used in a Sentence: He promised us a massive surprise, but it turned out to be a false alarm. / Don’t get excited about his promises because he is always a false alarm.
Similar Expressions: Disappointment / Fake threat
18. False friend
Definition: Someone who pretends to care about you while secretly wishing for your failure.
Used in a Sentence: She whispered mean rumors while smiling to my face like a false friend. / A false friend will abandon you the moment things get difficult.
Similar Expressions: Treacherous companion / Insincere buddy
19. Flatterer
Definition: Someone who gives excessive, insincere praise only to gain personal favors.
Used in a Sentence: He kept complimenting the teacher’s shoes, acting like a transparent flatterer. / Don’t trust a flatterer who only says nice things when he wants something.
Similar Expressions: Yes-man / Insincere sycophant
20. Fool’s gold
Definition: Something or someone that looks valuable and genuine on the outside but is actually worthless.
Used in a Sentence: That shiny rock he found on the playground turned out to be mere fool’s gold. / His generous offer of help was just fool’s gold when he walked away.
Similar Expressions: Worthless imitation / False treasure
21. Fraud
Definition: A person who deceives others by pretending to possess skills or traits they lack.
Used in a Sentence: He claimed he won the art contest, but everyone knew he was a fraud. / The fake expert was exposed as a complete fraud during the presentation.
Similar Expressions: Impostor / Cheat
22. Glass of cold water
Definition: Sometimes used ironically for a person whose cold, insincere personality refreshes nobody.
Used in a Sentence: Walking into his gloomy office felt like getting splashed with a glass of cold water. / Her chilly, fake greeting was about as welcoming as a glass of cold water.
Similar Expressions: Cold personality / Unwelcoming person
23. Green snake in the grass
Definition: A sneaky, hidden enemy who pretends to be harmless.
Used in a Sentence: My uncle warned me that classmate was a green snake in the grass. / Beware of that quiet student who acts nice but is a green snake in the grass.
Similar Expressions: Sneaky traitor / Hidden foe
24. Hypocrite
Definition: A person who pretends to have moral standards while doing the exact opposite.
Used in a Sentence: He tells everyone not to litter while dropping candy wrappers, making him a hypocrite. / Don’t be a hypocrite by breaking the very rules you set for us.
Similar Expressions: Two-faced person / Phony moralist
25. Impostor
Definition: Someone who tricks people by assuming a false identity or pretending to be skilled.
Used in a Sentence: The detective realized the stranger claiming to be the club manager was an impostor. / Don’t let an impostor take credit for your hard work.
Similar Expressions: Fake person / Fraud
26. In name only
Definition: A person who holds a title or friendship position but provides no genuine support.
Used in a Sentence: He was my study partner in name only because I did all the work alone. / The club president was a leader in name only and never organized meetings.
Similar Expressions: Nominal title / Fake role
27. Jack of all trades in disguise
Definition: A person who pretends to know everything about every topic to impress people.
Used in a Sentence: He tried to act like an expert on rockets, but he was just a jack of all trades in disguise. / Don’t pretend to understand computers like a know-it-all impostor.
Similar Expressions: Pretender / Fake expert
28. Kiss-up
Definition: Someone who is overly nice to authority figures insincerely to get ahead.
Used in a Sentence: He always cleans the teacher’s desk just to act like a annoying kiss-up. / Stop being such a kiss-up and earn your grades through honest work.
Similar Expressions: Flatterer / Teacher’s pet
29. Little tin god
Definition: A fake person who acts extremely arrogant and important like an almighty ruler.
Used in a Sentence: He struts around the playground acting like a little tin god just because he is team captain. / Nobody likes working with a little tin god who orders everyone around.
Similar Expressions: Arrogant phony / Pompous bully
30. Lone shark in sheep’s clothing
Definition: A dangerous or greedy person disguised as a harmless, friendly individual.
Used in a Sentence: That sweet-talking salesman turned out to be a shark in sheep’s clothing. / Be careful of people who act too friendly too fast like a wolf in sheep’s clothing.
Similar Expressions: Deceptive person / Hidden threat
31. Mask wearer
Definition: Someone who hides their true, unkind personality behind a polite public face.
Used in a Sentence: You never know what he is thinking because he is a constant mask wearer. / Once you get to know him, the polite mask wearer disappears to reveal a rude person.
Similar Expressions: Two-faced individual / Hidden personality
32. Mouthpiece
Definition: A person who simply repeats someone else’s fake opinions without thinking.
Used in a Sentence: He doesn’t have his own ideas; he is just a mouthpiece for the school bullies. / Stop acting like a mouthpiece for rumors you don’t understand.
Similar Expressions: Echo / Spokesperson for lies
33. Mutton dressed as lamb
Definition: An older person trying to act artificially young and fake.
Used in a Sentence: Wearing those trendy neon clothes made him look like mutton dressed as lamb at the party. / Keep your style natural instead of acting like mutton dressed as lamb.
Similar Expressions: Fake youth / Forced style
34. Painted doll
Definition: Someone who cares only about fake outward appearance and has no substance.
Used in a Sentence: She spent hours fixing her hair just to act like a painted doll who ignored everyone. / True friendship matters more than looking like a pretty painted doll.
Similar Expressions: Superficial person / Vain individual
35. Paper tiger
Definition: A person who looks fierce and threatening on the outside but is actually weak and fake.
Used in a Sentence: He threatened to tell the teacher, but he was just a paper tiger who never did anything. / Don’t be scared of his loud threats because he is a complete paper tiger.
Similar Expressions: Weak impostor / False threat
36. Phony
Definition: A completely insincere and fake person who pretends to be someone they are not.
Used in a Sentence: Everyone could tell he was a total phony when he bragged about winning a race he didn’t run. / Don’t trust a phony who changes his story every day.
Similar Expressions: Impostor / Fraudulent person
37. Plastic smile
Definition: A rigid, fake grin that shows no genuine warmth or happiness.
Used in a Sentence: She greeted us at the door with a stiff, plastic smile. / His plastic smile didn’t fool anyone into thinking he was glad we won.
Similar Expressions: Fake grin / Insincere expression
38. Poseur
Definition: A person who pretends to have a certain lifestyle or attitude to impress others.
Used in a Sentence: He carries a skateboard around but never rides it, acting like a total poseur. / Stop being a poseur and just wear what makes you comfortable.
Similar Expressions: Show-off / Pretender
39. Pretender
Definition: Someone who maintains a false appearance to deceive people around them.
Used in a Sentence: The talent show judge quickly realized the contestant was a mere pretender. / A true friend is honest, not a hidden pretender.
Similar Expressions: Fraud / Impostor
40. Smooth operator
Definition: A slick, charming person who uses fake sweetness to trick people.
Used in a Sentence: Watch out for that smooth operator trying to trade you broken toys. / He talks so nicely, but he is just a smooth operator with a hidden agenda.
Similar Expressions: Slick talker / Deceptive charmer
41. Snake oil salesman
Definition: A dishonest person who sells fake ideas or items using false promises.
Used in a Sentence: Don’t buy his story about magical pens because he is a modern snake oil salesman. / The traveling merchant acted like a classic snake oil salesman.
Similar Expressions: Con man / Dishonest merchant
42. Superficial soul
Definition: A person who cares only about surface details and lacks genuine depth or character.
Used in a Sentence: He only cares about wearing brand-name shoes like a shallow, superficial soul. / Look for kind friends instead of a superficial soul who only cares about looks.
Similar Expressions: Shallow person / Vain individual
43. Sweet talker
Definition: Someone who uses flattering, insincere words to manipulate others.
Used in a Sentence: He is a sweet talker who tries to get out of doing chores with nice compliments. / Don’t fall for his sweet talker routine.
Similar Expressions: Flatterer / Slick talker
44. Tartuffe
Definition: A classic literary term for a hypocritical, fake religious or moral person.
Used in a Sentence: He lectured everyone on honesty while hiding stolen pencils, acting like a true Tartuffe. / Don’t listen to that moralizing Tartuffe.
Similar Expressions: Hypocrite / Phony saint
45. Two-faced
Definition: A person who says nice things to your face and mean things behind your back.
Used in a Sentence: I can’t stand being around two-faced people who smile at you and gossip later. / She proved she was two-faced when she agreed with both arguing sides.
Similar Expressions: Deceitful / Backstabbing
46. Uncle Tom
Definition: Sometimes used in slang to describe someone who acts insincerely to please authority.
Used in a Sentence: He changed his opinions just to please the boss, acting like an insincere pleaser. / Stand up for your real thoughts instead of acting like a fake follower.
Similar Expressions: Pleaser / Sycophant
47. Walking contradiction
Definition: A person whose words and fake actions never match up logically.
Used in a Sentence: He claims to love animals but steps on bugs on purpose, making him a walking contradiction. / Her advice is a walking contradiction to how she actually behaves.
Similar Expressions: Inconsistent person / Phony individual
48. Weathercock
Definition: A person who constantly changes their loyalties like a spinning wind vane.
Used in a Sentence: He is a political weathercock who supports whichever team is winning. / You can’t rely on a weathercock who changes his mind every minute.
Similar Expressions: Fickle person / Turncoat
49. Whited sepulchre
Definition: A biblical term for a person who looks good on the outside but is corrupt inside.
Used in a Sentence: His polite manners hid a cruel heart like a whited sepulchre. / Don’t be fooled by a whited sepulchre who hides bad intentions behind nice words.
Similar Expressions: Corrupt phony / Deceptive person
50. Wolf in sheep’s clothing
Definition: A dangerous, fake person who hides behind a kind and gentle appearance.
Used in a Sentence: The sneaky trickster was a wolf in sheep’s clothing trying to steal our game pieces. / Be careful of strangers who act too sweet; they might be a wolf in sheep’s clothing.
Similar Expressions: Hidden enemy / Deceptive threat
Exercise to Practice
- Don’t believe his sweet compliments because he is just an actor playing a part.
- Trusting him was a mistake because he turned out to be a total backstabber who helped me study every day.
- She is such a chameleon that she agrees with whatever group she is standing near.
- He cried crocodile tears when he got caught breaking the rule, but he wasn’t sorry at all.
- A fair-weather friend will abandon you the moment things get difficult.
- Everyone could tell he was a total phony when he bragged about winning a race he didn’t run.
- He carries a skateboard around but never rides it, acting like a total poseur.
- The sneaky trickster was a wolf in sheep’s clothing trying to steal our game pieces.
- Watch out for that smooth operator trying to trade you broken toys.
- She whispered mean rumors while smiling to my face like a false friend who loved me dearly.
- He lectured everyone on honesty while hiding stolen pencils, acting like a true Tartuffe.
- I can’t stand being around two-faced people who smile at you and gossip later.
- That shiny rock he found on the playground turned out to be genuine gold worth a million dollars.
- He tells everyone not to litter while dropping candy wrappers, making him a hypocrite.
- Behind his polite, fake smile, he was actually quite annoyed.
Answer Key
- True
- False
- True
- True
- True
- True
- True
- True
- True
- False
- True
- True
- False
- True
- True
Conclusion
Learning these idioms helps you describe dishonest, insincere, and untrustworthy people using fun and descriptive language. Try using a few of these expressions when writing stories or talking about characters in your favorite books.
Frequently Asked Questions
What are some common idioms for a fake person?
Common idioms for a fake person include phrases like two-faced, wolf in sheep’s clothing, and backstabber. These expressions help describe insincere, untrustworthy, and deceitful individuals in daily life.
Why do we use idioms to describe fake people?
Idioms give us vivid, memorable ways to express character traits that standard words sometimes cannot capture. They make stories and descriptions of tricky personalities much more engaging to read.
How can I practice using these idioms?
You can practice by using these phrases when writing stories about villains or tricky characters in adventure books. Matching them to everyday lessons about honesty is also very helpful.
Are these idioms always meant to be serious?
Many of these expressions describe serious untrustworthiness, but some can be used humorously when talking about copycats or show-offs. Context helps you understand the specific tone.
Can idioms help me understand English stories better?
Yes, recognizing these expressions helps you understand character motives, plot twists, and hidden intentions in books and movies much more clearly.
