29 Idioms for Crazy

We all encounter moments when things get a little out of control, absurd, or just plain crazy. Luckily, English offers a treasure trove of idioms that vividly express these out-of-the-ordinary moments, whether it’s a situation that’s spiraling out of control, someone acting unusually wild, or even a thought that’s completely illogical. From “off the wall” to “mad as a hatter,” these idioms help us describe what’s going on when the world feels upside down.

In this article, we’ll explore 29 idioms for crazy that bring humor and color to your descriptions of wild moments, chaotic situations, or eccentric behavior. These idioms will allow you to express just how outlandish things can get and add some fun to your language.

1. Off the wall

Meaning: Something that is unconventional, bizarre, or unexpected
In a Sentence:
– “Her idea for the party theme was totally off the wall, but everyone loved it.”
– “He made an off-the-wall comment during the meeting that shocked everyone.”
Other Ways to Say: Unusual / Out of the ordinary

2. Mad as a hatter

Meaning: A person who is completely crazy or eccentric
In a Sentence:
– “He’s mad as a hatter if he thinks that plan will work!”
– “She’s always been a bit mad as a hatter, with her strange and unique ways.”
Other Ways to Say: Eccentric / Wild

3. Like a bull in a china shop

Meaning: Someone who is clumsy or reckless, often causing chaos or damage in the process
In a Sentence:
– “When he joined the team, he was like a bull in a china shop, disrupting everything.”
– “She’s great at her job, but sometimes she’s like a bull in a china shop when she gets too excited.”
Other Ways to Say: Clumsy / Reckless

4. Not playing with a full deck

Meaning: A person who is mentally unstable, irrational, or not thinking clearly
In a Sentence:
– “I think he’s not playing with a full deck if he believes that’s going to work.”
– “She’s acting a little strange; I think she’s not playing with a full deck.”
Other Ways to Say: Not all there / Off-kilter

5. Off one’s rocker

Meaning: To behave in a very strange, irrational, or insane way
In a Sentence:
– “You must be off your rocker if you think I’ll agree to that!”
– “I think she’s off her rocker after all the drama she’s been creating lately.”
Other Ways to Say: Crazy / Unhinged

6. Out of your mind

Meaning: To act in a way that seems irrational or extremely unusual
In a Sentence:
– “You must be out of your mind if you think I’ll ever agree to that deal.”
– “He’s out of his mind if he’s planning to quit his job without a backup plan.”
Other Ways to Say: Insane / Absurd

7. Barking mad

Meaning: Completely crazy or mad
In a Sentence:
– “I think she’s barking mad to quit her job and travel the world without a plan.”
– “You’re barking mad if you think this plan will work!”
Other Ways to Say: Completely crazy / Insane

8. Losing your marbles

Meaning: To lose one’s ability to think rationally or to go crazy
In a Sentence:
– “After working non-stop for weeks, I’m starting to feel like I’m losing my marbles.”
– “She’s completely losing her marbles over a small mistake at work.”
Other Ways to Say: Losing it / Going crazy

9. As crazy as a loon

Meaning: To behave in an eccentric, wild, or extremely crazy way
In a Sentence:
– “He’s as crazy as a loon if he thinks he can get away with that.”
– “Her antics at the party made her seem as crazy as a loon.”
Other Ways to Say: Completely crazy / Wild

10. Like a headless chicken

Meaning: To run around in a chaotic or disorganized way, often not achieving anything
In a Sentence:
– “I was running around like a headless chicken trying to get everything ready before the event.”
– “He’s been working like a headless chicken but still hasn’t finished anything.”
Other Ways to Say: Chaotic / Frantic

11. Mad as a bag of frogs

Meaning: Completely insane or very strange in behavior
In a Sentence:
– “He’s mad as a bag of frogs if he thinks this plan will work.”
– “She’s been acting mad as a bag of frogs lately, saying the weirdest things.”
Other Ways to Say: Eccentric / Crazy

12. Batty as a fruitcake

Meaning: To be very eccentric, crazy, or irrational
In a Sentence:
– “You’re as batty as a fruitcake if you think that idea will succeed!”
– “Her ideas were batty as a fruitcake, and no one knew how to take them seriously.”
Other Ways to Say: Completely crazy / Off the wall

13. A few sandwiches short of a picnic

Meaning: To be slightly crazy or not quite mentally stable
In a Sentence:
– “I think he’s a few sandwiches short of a picnic if he believes that conspiracy theory.”
– “She’s a few sandwiches short of a picnic, always making strange decisions.”
Other Ways to Say: Not all there / A little off

14. In a world of your own

Meaning: To be acting or thinking in a way that is detached from reality, often in a bizarre or crazy way
In a Sentence:
– “He’s always in a world of his own, completely unaware of what’s happening around him.”
– “She was so absorbed in her work that she seemed to be in a world of her own.”
Other Ways to Say: Detached / Lost in thought

15. One fry short of a Happy Meal

Meaning: To be somewhat crazy or not mentally all there
In a Sentence:
– “He’s one fry short of a Happy Meal if he thinks he can pull off that stunt.”
– “She’s one fry short of a Happy Meal, always doing unpredictable things.”
Other Ways to Say: Slightly off / Not all there

16. Out of control

Meaning: Something that is becoming unmanageable, chaotic, or overly wild
In a Sentence:
– “The party got completely out of control when everyone started dancing on the tables.”
– “The situation at work is out of control; I don’t think we can keep up with the demands.”
Other Ways to Say: Unmanageable / Wild

17. On a wild goose chase

Meaning: To pursue something that is impossible or pointless, often leading nowhere
In a Sentence:
– “We’ve been on a wild goose chase trying to find a solution to this problem.”
– “Searching for that old document feels like a wild goose chase—it’s probably lost forever.”
Other Ways to Say: Pointless pursuit / Fruitless endeavor

18. All over the place

Meaning: To be disorganized, scattered, or chaotic in thought or action
In a Sentence:
– “She’s all over the place today, bouncing from task to task without finishing anything.”
– “The meeting was all over the place, with everyone talking at once and no clear direction.”
Other Ways to Say: Disorganized / Unfocused

19. Off the beaten path

Meaning: Something unusual, unconventional, or far from the usual way of doing things
In a Sentence:
– “That’s an off-the-beaten-path idea, but it could work if we try it out.”
– “His approach to solving problems is always off the beaten path, but it’s refreshing.”
Other Ways to Say: Unconventional / Unusual

20. A loose cannon

Meaning: A person who is unpredictable, reckless, and often causes problems because of their erratic behavior
In a Sentence:
– “He’s a loose cannon at work, never knowing what he’ll do next.”
– “She’s always acting like a loose cannon, causing trouble wherever she goes.”
Other Ways to Say: Unpredictable / Wild

21. As mad as a March hare

Meaning: To be completely crazy or acting in a wild and unpredictable way
In a Sentence:
– “He’s as mad as a March hare when he gets excited about new ideas.”
– “She was as mad as a March hare, jumping from one idea to the next without thinking.”
Other Ways to Say: Eccentric / Wild

22. A loose screw

Meaning: A person who is mentally unstable or behaving erratically
In a Sentence:
– “I think he’s got a loose screw if he thinks that idea will work.”
– “She’s acting like she’s got a loose screw, making decisions that make no sense.”
Other Ways to Say: Unstable / Not all there

23. Like a bat out of hell

Meaning: To move or act very quickly, often in a reckless or uncontrolled manner
In a Sentence:
– “He came running into the room like a bat out of hell, without stopping to think.”
– “She left the party like a bat out of hell when things started getting awkward.”
Other Ways to Say: In a rush / Reckless speed

24. Off the rails

Meaning: A situation or person that has gone completely out of control or is no longer functioning normally
In a Sentence:
– “The event went off the rails when the caterer didn’t show up on time.”
– “His behavior has gone off the rails since the last argument; I don’t know how to fix it.”
Other Ways to Say: Out of control / Chaotic

25. Not the sharpest tool in the shed

Meaning: To be not very intelligent or to act in a silly or foolish way
In a Sentence:
– “He’s not the sharpest tool in the shed, but he means well.”
– “I hate to say it, but sometimes she’s just not the sharpest tool in the shed.”
Other Ways to Say: Not very bright / A bit slow

26. Like a rabbit in headlights

Meaning: To be stunned, paralyzed, or overwhelmed, especially in a difficult situation
In a Sentence:
– “When they asked him about the mistake, he froze up like a rabbit in headlights.”
– “She stood there like a rabbit in headlights when the boss called her out for being late.”
Other Ways to Say: Paralyzed by fear / Stunned

27. Jump off the deep end

Meaning: To suddenly act in an extreme or irrational way, usually without thinking
In a Sentence:
– “She jumped off the deep end when she heard the news, not taking time to consider her options.”
– “He always jumps off the deep end when things don’t go his way.”
Other Ways to Say: Overreact / Go overboard

28. Like a fox in a henhouse

Meaning: Someone who behaves in a way that causes chaos or trouble, often because they shouldn’t be in that situation
In a Sentence:
– “He’s like a fox in a henhouse, causing trouble wherever he goes.”
– “Letting her take over the project was like a fox in a henhouse—everything went wrong.”
Other Ways to Say: Troublemaker / Disruptive force

29. Off one’s rocker

Meaning: To be acting or thinking in an irrational or crazy way
In a Sentence:
– “He must be off his rocker if he thinks I’m going to agree to that deal.”
– “She was acting completely off her rocker, yelling at the top of her lungs in public.”
Other Ways to Say: Mad / Unhinged

Practice Exercise

Fill in the blanks using the correct idiom from the list:

1. She must be __________ if she thinks we can finish this project in a day.
2. His plan was completely __________; it made no sense at all.
3. After hearing the news, I was __________, not knowing how to respond.
4. His behavior is so __________, I don’t know if I can handle it anymore.
5. I can’t believe she said that—she’s really __________ with her opinions.
6. He always __________ when something goes wrong; he doesn’t think before acting.
7. When the boss gave him that task, he went __________, making it a disaster.
8. The meeting was completely __________, no one was getting anything done.
9. He’s been acting like __________, making odd decisions without considering the consequences.
10. The idea she suggested was totally __________, and no one took it seriously.
11. She’s been running around like a __________, trying to get everything done.
12. He’s __________ with all the deadlines, and now he’s late for everything.
13. The meeting got __________ when everyone started arguing over small details.
14. His new business idea was a complete __________, nobody was interested.
15. She’s always acting __________, talking about things that make no sense.
16. He’s always __________, managing work and personal life with ease.
17. I feel like I’m __________ trying to keep up with all the changes.
18. His jokes are so __________, they often confuse everyone in the room.
19. The way she’s been acting makes her look like __________, unpredictable and out of control.
20. I think he’s __________ if he thinks that plan will succeed.
21. After hearing that news, I was __________, unsure how to handle it.
22. She’s always making decisions without thinking; she’s __________.
23. That was a __________ suggestion, no one took it seriously.
24. He’s completely __________ with his plans; nothing is going right.
25. I don’t think she’s __________; her actions have been so bizarre.
26. His idea is __________; it has no chance of working.
27. The whole situation feels like a __________, and I don’t know where to begin.
28. She keeps bringing up the same thing over and over, like a __________.
29. It’s crazy; they’re acting like __________, not taking responsibility for their actions.

Answer Key

1. Off one’s rocker
2. Like a fox in a henhouse
3. Like a rabbit in headlights
4. A loose cannon
5. Mad as a bag of frogs
6. Jump off the deep end
7. Off the rails
8. A hot mess
9. Not the sharpest tool in the shed
10. Like a bat out of hell
11. Running around like a headless chicken
12. Drowning in work
13. All over the place
14. A lead balloon
15. Like a bag of frogs
16. On the go
17. Running ragged
18. Barking mad
19. A rabbit in a lion’s den
20. Not playing with a full deck
21. Out of control
22. Off the wall
23. A wild goose chase
24. Out of your mind
25. Mad as a hatter
26. A few fries short of a Happy Meal
27. Like a train wreck
28. Like a broken record
29. Like a bull in a china shop

Conclusion

Describing crazy or chaotic situations, actions, or people can be challenging, but idioms for crazy provide a fun and vivid way to express just how out of control things can feel. Whether you’re describing someone’s irrational behavior, a wild event, or a completely unpredictable situation, these idioms help bring clarity to the madness.

By mastering these idioms, you can enhance your communication skills, whether you’re discussing hectic workdays, eccentric individuals, or crazy moments in life. Using these idioms will allow you to express yourself with greater creativity and impact, giving your language more color and personality.