Idioms are fun phrases that mean something different from the actual words inside them. People use them to make conversation more colorful, interesting, and full of feeling. Today, you will learn a large group of helpful idioms related to insincere characters and fake people.
In this lesson, we’ll look at idioms for fake person that mean insincere individuals and fake people. Let’s get started and explore some of these helpful expressions.
Idioms for Fake Person
1. A bad egg
Meaning: Someone who cannot be trusted and frequently causes trouble behind your back.
For Example: Do not trust him with your secrets because he is known to be a bad egg. / The student realized his buddy was a bad egg when he lied.
Other Ways to Say: Unreliable person / Untrustworthy soul
2. A wolf in sheep’s clothing
Meaning: A dangerous, fake person who pretends to be nice while hiding bad intentions.
For Example: He seemed friendly at first, but turned out to be a wolf in sheep’s clothing. / Be careful of classmates who act like a wolf in sheep’s clothing.
Other Ways to Say: Deceptive person / Hidden enemy
3. All talk and no action
Meaning: Someone who makes big promises of friendship, but never actually helps you.
For Example: He promised to help clean my bicycle, but he is all talk and no action. / Do not rely on her because she is all talk and no action.
Other Ways to Say: Empty promises / Big talker
4. Backstabber
Meaning: A fake person who betrays your trust when you are not looking.
For Example: Sharing secrets with a backstabber is a big mistake. / He found out his trusted companion was actually a backstabber.
Other Ways to Say: Traitor / Betrayer
5. Fair-weather friend
Meaning: Someone who is only friendly when things are good, but leaves when times get tough.
For Example: When I lost my favorite toy, my fair-weather friend walked away. / You can tell who truly cares and who is just a fair-weather friend.
Other Ways to Say: Untrustworthy pal / Temporary buddy
6. False friend
Meaning: A person who pretends to like you, but is actually dishonest.
For Example: Discovering he was a false friend made her feel very sad. / A false friend will smile to your face and gossip behind your back.
Other Ways to Say: Insincere companion / Pretend buddy
7. Fox in the hen house
Meaning: A sneaky, untrustworthy person allowed into a group where they cause harm.
For Example: Letting him join our club was like inviting a fox in the hen house. / The tricky student acted like a fox in the hen house during group work.
Other Ways to Say: Sneaky intruder / Hidden threat
8. Judas kiss
Meaning: A friendly greeting or gesture from someone who plans to betray you.
For Example: His sweet apology felt like a Judas kiss after what he did. / Beware of a Judas kiss from someone who pretends to care.
Other Ways to Say: Betrayal gesture / Fake kindness
9. Leopard cannot change its spots
Meaning: A fake person who keeps acting dishonestly because it is their nature.
For Example: He promised to stop lying, but a leopard cannot change its spots. / Do not expect him to be loyal because a leopard cannot change its spots.
Other Ways to Say: People do not change / True nature remains
10. Lip service
Meaning: Saying you support someone with words, but showing no loyalty with actions.
For Example: He only gave lip service to helping with the project. / True loyalty means more than just paying lip service to friendship.
Other Ways to Say: Empty words / Insincere support
11. Mock modesty
Meaning: Acting humble on the outside while secretly plotting to look better than you.
For Example: Her fake praise was just mock modesty to hide her jealousy. / Do not fall for his mock modesty when he acts innocent.
Other Ways to Say: Insincere humility / Fake modesty
12. Painted smile
Meaning: A fake, insincere smile worn by someone who dislikes you.
For Example: He greeted me at the door with a cold, painted smile. / Her painted smile could not hide her unkind thoughts.
Other Ways to Say: Fake grin / Insincere expression
13. Paper tiger
Meaning: Someone who acts tough and threatening, but is actually weak and fake.
For Example: The school bully turned out to be a paper tiger when challenged. / Do not fear his threats because he is just a paper tiger.
Other Ways to Say: Fake tough guy / Weak threat
14. Parasite
Meaning: A fake person who hangs around only to use your things and take your snacks.
For Example: He only talks to me when he wants my markers, acting like a parasite. / Do not let a parasite ruin your lunch break.
Other Ways to Say: User / Free loader
15. Phonus balonus
Meaning: A silly old phrase describing someone who is fake and untruthful.
For Example: Do not believe his wild stories about being rich because it is all phonus balonus. / His promise of loyalty was total phonus balonus.
Other Ways to Say: Nonsense / Fake talk
16. Play both sides
Meaning: Being friendly to you while also hanging out with your rival.
For Example: You cannot play both sides in an argument and expect to keep true friends. / He liked to play both sides during playground disputes.
Other Ways to Say: Be two-faced / Stay neutral to deceive
17. Play possum
Meaning: Acting harmless or innocent when caught being a bad person.
For Example: When the teacher asked who started the rumor, he tried to play possum. / Do not let him play possum after he broke your trust.
Other Ways to Say: Play innocent / Feign ignorance
18. Poison the well
Meaning: A fake person spreading lies to turn other people against you.
For Example: He tried to poison the well by telling false stories to our classmates. / Gossip is an easy way to poison the well of trust.
Other Ways to Say: Spread rumors / Ruin trust
19. Pretender
Meaning: Someone who pretends to be your loyal companion, but is actually dishonest.
For Example: We soon realized he was just a pretender who wanted popular friends. / Do not trust a pretender with your personal diary.
Other Ways to Say: Fake person / Imposter
20. Prowling cat
Meaning: A sneaky person who listens in on your conversations to gossip later.
For Example: Watch out for him lurking by the lockers like a prowling cat. / She acted like a prowling cat listening to our secret plans.
Other Ways to Say: Sneaky listener / Gossip spy
21. Put on an act
Meaning: Pretending to be a kind and caring person when you are actually selfish.
For Example: Stop putting on an act and be honest with your classmates. / She was just putting on an act to win the class election.
Other Ways to Say: Fake it / Put on airs
22. Rotten apple
Meaning: One dishonest, fake person who spoils a friendly group.
For Example: The teacher removed the dishonest student so he would not act like a rotten apple. / One rotten apple can ruin the trust in a club.
Other Ways to Say: Bad influence / Spoiled member
23. Run with the hare and hunt with the hounds
Meaning: A fake person who tries to secretly support both sides of a fight.
For Example: He tried to run with the hare and hunt with the hounds during our argument. / You cannot run with the hare and hunt with the hounds when loyalty matters.
Other Ways to Say: Be two-faced / Double dealer
24. Salt in the wound
Meaning: When a fake person laughs after you experience a hard time.
For Example: Mocking my low test score felt like rubbing salt in the wound. / A true friend helps, but a fake person adds salt in the wound.
Other Ways to Say: Make it worse / Add pain
25. Serpent in your bosom
Meaning: A close companion who betrays you after you treated them with kindness.
For Example: Helping him with his homework only to have him steal my idea felt like a serpent in your bosom. / Beware of a serpent in your bosom disguised as a pal.
Other Ways to Say: Traitorous friend / Ungrateful snake
26. Shadow person
Meaning: Someone who only follows you when it is convenient, but disappears in trouble.
For Example: He is just a shadow person who vanishes when homework gets hard. / Do not count on a shadow person during difficult times.
Other Ways to Say: Unreliable companion / Fair-weather friend
27. Shiny exterior
Meaning: Looking like a wonderful person on the outside, but being mean inside.
For Example: Her shiny exterior hid a very unkind and untrustworthy heart. / Do not judge people by a shiny exterior alone.
Other Ways to Say: Deceptive look / False charm
28. Snake in the grass
Meaning: A hidden enemy who smiles at you while planning to betray you.
For Example: He acted so sweet, but turned out to be a snake in the grass. / Never trust a snake in the grass who gossips behind your back.
Other Ways to Say: Traitor / Hidden enemy
29. Sour grapes
Meaning: Acting like you do not like someone because they dropped your fake relationship.
For Example: He said he never liked my club anyway, but that was just sour grapes. / Do not show sour grapes when fake people leave.
Other Ways to Say: Fake dislike / Bitter reaction
30. Speak with a forked tongue
Meaning: Lying and saying one thing to your face while saying another behind your back.
For Example: We caught him speaking with a forked tongue about our group project. / Do not trust anyone speaking with a forked tongue.
Other Ways to Say: Lie / Be two-faced
31. Spin a yarn
Meaning: Making up false stories to trick people around you.
For Example: He loved to spin a yarn about why he forgot his homework. / Do not believe his wild tales because he loves to spin a yarn.
Other Ways to Say: Tell lies / Make up stories
32. Stabbing in the back
Meaning: The cruel act of betraying a trusting person.
For Example: Spreading rumors about me was a total stabbing in the back. / He committed a terrible stabbing in the back by sharing my secret.
Other Ways to Say: Betrayal / Treason
33. Sugar-coated lies
Meaning: Untruthful words made to sound sweet so you will trust a fake person.
For Example: Do not believe his sugar-coated lies about helping you study. / Her sweet compliments were just sugar-coated lies.
Other Ways to Say: False sweetness / Deceptive words
34. Thorn in your side
Meaning: A constant annoying person who pretends to be nice.
For Example: That classmate who always teases me secretly is a real thorn in my side. / Deal with that thorn in your side by ignoring their gossip.
Other Ways to Say: Annoyance / Nuisance
35. Throw under the bus
Meaning: Blaming someone else to save yourself from trouble.
For Example: When the teacher found the mess, he tried to throw me under the bus. / A loyal person will never throw you under the bus.
Other Ways to Say: Betray / Shift blame
36. Too good to be true
Meaning: A personality or promise that seems wonderful, but turns out fake.
For Example: When he offered to do all my chores for free, it seemed too good to be true. / Their sudden kindness felt too good to be true.
Other Ways to Say: Suspiciously nice / Fake offer
37. Trojan horse
Meaning: A hidden trick where a fake person sneaks into your group to cause trouble.
For Example: We realized the new classmate was like a Trojan horse spreading rumors. / Be careful accepting new kids who act like a Trojan horse.
Other Ways to Say: Hidden trap / Deceptive gift
38. Turncoat
Meaning: Someone who switches sides and betrays their peers for personal gain.
For Example: He became a turncoat and joined the rival club just to win a prize. / Nobody likes a turncoat who abandons his loyal buddies.
Other Ways to Say: Traitor / Switcher
39. Two faces
Meaning: Showing one kind expression to you and a mean one behind your back.
For Example: I cannot stand being around someone who has two faces. / Her two faces became obvious when we heard her gossip.
Other Ways to Say: Two-faced / Insincere
40. Two-faced
Meaning: Dishonest and insincere in your daily interactions.
For Example: Calling someone your best friend while gossiping about them is being two-faced. / He proved to be two-faced when the secret got out.
Other Ways to Say: Deceitful / Insincere
41. Underhanded trick
Meaning: A sneaky, dishonest action done by a fake person.
For Example: Hiding my gym shoes was an underhanded trick. / Do not play underhanded tricks on your classmates.
Other Ways to Say: Sneaky move / Dishonest act
42. Untrustworthy soul
Meaning: A person who repeatedly breaks promises and betrays confidence.
For Example: He proved to be an untrustworthy soul when he shared my diary. / Never lend your favorite video game to an untrustworthy soul.
Other Ways to Say: Unreliable person / Liar
43. Velvet glove, iron fist
Meaning: Acting sweet on the outside while being mean and controlling inside.
For Example: The club leader ruled with a velvet glove, iron fist approach. / Her friendly voice hid a demanding, unkind nature.
Other Ways to Say: Fake kindness / Harsh control
44. Veneer of friendship
Meaning: A thin, fake layer of friendliness that hides true dislike.
For Example: Their polite conversation masked a thin veneer of friendship. / We could easily see through their veneer of friendship.
Other Ways to Say: Fake bond / Superficial tie
45. Viper in your bosom
Meaning: A trusted person who turns out to be a cruel traitor.
For Example: Trusting him was like warming a viper in your bosom. / She felt betrayed by the viper in your bosom who spread her secrets.
Other Ways to Say: Traitorous companion / Ungrateful snake
46. Walk all over you
Meaning: When a fake person takes advantage of your kindness.
For Example: Do not let him borrow your toys every day or he will walk all over you. / Stand up for yourself so people do not walk all over you.
Other Ways to Say: Take advantage / Dominate
47. Wash your hands of someone
Meaning: Deciding to stop dealing with a fake and dishonest person.
For Example: After he lied again, I decided to wash my hands of him. / It is best to wash your hands of toxic individuals.
Other Ways to Say: Give up on / Cut ties
48. Watered-down loyalty
Meaning: Support that is weak, fake, and lacks real meaning.
For Example: His promise to help us was just watered-down loyalty. / We needed real help, not watered-down loyalty.
Other Ways to Say: Weak support / Fake backing
49. Wear a mask
Meaning: Hiding your true, mean personality behind a friendly smile.
For Example: He would wear a mask of kindness whenever the teacher was near. / It is hard to trust someone who continues to wear a mask.
Other Ways to Say: Hide true self / Pretend
50. Whispering campaign
Meaning: Spreading secret, mean rumors behind someone’s back.
For Example: The fake person started a whispering campaign against her. / Pay no attention to their silly whispering campaign.
Other Ways to Say: Spread gossip / Rumor mill
51. White lie
Meaning: A small untruth, but often used by fake people to avoid honesty.
For Example: He called it a white lie, but it was really a dishonest excuse. / Do not tell white lies to your classmates.
Other Ways to Say: Small untruth / Minor fib
52. Windbag
Meaning: Someone who talks big about being nice, but never proves it.
For Example: Pay no attention to that windbag who promises free tickets. / He acted like a windbag during lunch break.
Other Ways to Say: Boaster / Empty talker
53. Worm your way in
Meaning: Gaining someone’s trust dishonestly just to find out secrets.
For Example: She tried to worm her way into our group just to spread gossip. / Watch out for people who worm their way in with fake smiles.
Other Ways to Say: Sneak in / Insinuate yourself
54. Wrong ‘un
Meaning: A slang phrase for a shady, untrustworthy person.
For Example: Our parents warned us that the new kid might be a wrong ‘un. / Trust your instincts if someone feels like a wrong ‘un.
Other Ways to Say: Shady person / Bad character
55. Yellow streak
Meaning: Showing cowardice and betraying someone when trouble starts.
For Example: When the teacher asked questions, his yellow streak showed as he blamed me. / He showed a yellow streak by running away from his promise.
Other Ways to Say: Cowardice / Fearful betrayal
56. Zero loyalty
Meaning: Having no faithfulness or honesty in a person at all.
For Example: Finding out he shared my secret showed he had zero loyalty. / You cannot trust someone who has zero loyalty.
Other Ways to Say: Unfaithful / No dedication
57. Zip your lip
Meaning: A warning to keep secrets safe from people who gossip.
For Example: Zip your lip and do not tell the fake person our plan. / We had to zip our lip around the gossips.
Other Ways to Say: Keep quiet / Silence
58. Phoney baloney
Meaning: An expression meaning someone is completely fake and dishonest.
For Example: His apology sounded like total phoney baloney to me. / Do not listen to that phoney baloney excuse.
Other Ways to Say: Fake / Nonsense
59. Two-faced snake
Meaning: A deceptive person who switches sides and gossips.
For Example: We realized he was a two-faced snake who could not be trusted. / Watch out for any two-faced snake in the group.
Other Ways to Say: Deceiver / Traitor
60. Double agent
Meaning: Someone who pretends to be on your side while secretly helping rivals.
For Example: He acted like a double agent during our club elections. / Finding out he was a double agent shocked our team.
Other Ways to Say: Secret traitor / Deceiver
Exercise to Practice
- Do not trust him with your secrets because he is known to be a bad ________.
- He seemed friendly at first, but turned out to be a wolf in sheep’s ________.
- Sharing secrets with a backstabber is a big ________.
- When I lost my favorite toy, my fair-weather ________ walked away.
- He promised to help clean my bicycle, but he is all talk and no ________.
- Letting him join our club was like inviting a fox in the hen ________.
- His sweet apology felt like a Judas ________ after what he did.
- He liked to play both ________ during playground disputes.
- When the teacher asked who started the rumor, he tried to play ________.
- He tried to poison the ________ by telling false stories to our classmates.
- Hiding my gym shoes in the locker was an underhanded ________.
- When the teacher found the classroom mess, he tried to throw me under the ________.
- Spreading false rumors about me behind my back was a total stabbing in the ________.
- After he lied to me again, I decided to wash my ________ of him.
- Zip your ________ and do not tell the gossips about our weekend plan.
Answer Key
- egg
- clothing
- mistake
- friend
- action
- house
- kiss
- sides
- possum
- well
- trick
- bus
- back
- hands
- lip
Conclusion
Learning these idioms helps you recognize untrustworthy behavior and identify fake people in your daily life. When you know how to use these phrases, talking about relationships and trust becomes much clearer.
Try using one or two of these expressions the next time you discuss characters in a story or talk about loyalty with your friends. You will see how much wisdom and color they bring to your conversations!
