We often use idiomatic expressions to describe people who might not be the sharpest tools in the shed.
In this article, we’ll explore idioms for stupidity, offering clear explanations of what each phrase means and how to use them in a sentence.
So, let’s dive into the world of idioms that describe not-so-smart situations and individuals.

What is an idiom for stupid?
Idioms are phrases that have meanings beyond their individual words. Idioms for stupidity are expressions used to describe someone’s lack of intelligence or their inability to grasp simple concepts.
They are often used humorously to lighten the mood or gently tease someone. Let’s explore these idioms and discover their meanings and usage.
Idiom | Meaning | Example Sentence |
---|---|---|
Dumb as a doorknob | Extremely unintelligent or lacking common sense. | Despite clear instructions, he couldn’t figure it out; he’s dumb as a doorknob. |
Thick as two short planks | Very stupid or intellectually challenged. | Trying to explain the concept to him was futile; he’s thick as two short planks. |
Not the brightest crayon in the box | Not very intelligent or lacking in mental acuity. | Sarah means well, but she’s not the brightest crayon in the box when it comes to solving problems. |
A few fries short of a Happy Meal | Lacking intelligence or common sense. | John’s idea of fixing the car was a disaster; he’s a few fries short of a Happy Meal. |
Couldn’t pour water out of a boot with instructions on the heel | Utterly incapable of performing even the simplest tasks. | Watching him try to set up the tent was comical; he couldn’t pour water out of a boot with instructions on the heel. |
One sandwich short of a picnic | Lacking intelligence or rational thinking. | His conspiracy theories make him seem one sandwich short of a picnic. |
Not playing with a full deck | Not mentally stable or lacking intelligence. | He keeps believing those wild rumors; it’s clear he’s not playing with a full deck. |
A few cards shy of a full deck | Lacking intelligence or common sense. | Her decision to quit her job without a backup plan suggests she’s a few cards shy of a full deck. |
Missing a few screws | Lacking intelligence or rational thinking. | After hearing his bizarre explanations, it’s clear he’s missing a few screws. |
All foam, no beer | Superficial or appearing smarter than one actually is. | He talks a big game, but it’s all foam, no beer; he lacks substance. |
Not the sharpest tool in the shed | Lacking intelligence or mental acuity. | When it comes to solving puzzles, she’s not the sharpest tool in the shed. |
One brick short of a load | Lacking intelligence or rational thinking. | His bizarre beliefs make him seem one brick short of a load. |
A few bricks shy of a load | Lacking intelligence or common sense. | Her inability to follow basic instructions suggests she’s a few bricks shy of a load. |
A few grapes short of a fruit salad | Lacking intelligence or rationality. | His wild theories make him appear a few grapes short of a fruit salad. |
Two tacos short of a combination plate | Not very intelligent or lacking mental acuity. | Trying to explain the concept to him was like talking to someone two tacos short of a combination plate. |
Missing the plot | Failing to understand or comprehend a situation. | When it comes to technology, she’s often missing the plot. |
Not the brightest bulb in the box | Lacking intelligence or mental acuity. | His constant confusion suggests he’s not the brightest bulb in the box. |
Missing the boat | Failing to take advantage of an opportunity or failing to understand something. | When it comes to investments, he always seems to be missing the boat. |
One wheel short of a wagon | Lacking intelligence or rational thinking. | Her bizarre actions make her seem one wheel short of a wagon. |
The lights are on but nobody’s home | Someone appears to be present but lacks mental alertness or is not paying attention. | During the meeting, he was staring blankly; it’s like the lights are on but nobody’s home. |
Not the sharpest knife in the drawer | Lacking intelligence or mental acuity. | When it comes to solving complex problems, he’s not the sharpest knife in the drawer. |
A couple of fries short of a Happy Meal | Lacking intelligence or rational thinking. | Her strange choices make her seem a couple of fries short of a Happy Meal. |
Can’t find their way out of a paper bag | Lacking basic navigation skills or problem-solving abilities. | He struggled with the simplest directions; it’s like he can’t find his way out of a paper bag. |
One can short of a six-pack | Lacking intelligence or rational thinking. | His constant blunders suggest he’s one can short of a six-pack. |
Not the swiftest horse in the stable | Lacking intelligence or mental acuity. | When it comes to making decisions, she’s not the swiftest horse in the stable. |
A few sandwiches short of a picnic | Lacking intelligence or rational thinking. | His strange behavior makes him appear a few sandwiches short of a picnic. |
A few clowns short of a circus | Lacking intelligence or rationality. | Their bizarre theories make them seem a few clowns short of a circus. |
Describing someone as stupid is like saying they have a foggy windshield, making it hard for them to see the road ahead. For more comparisons to describe someone as stupid, you can check this link: Similes for stupid. And for a variety of metaphors related to stupidity, you can explore this link: Metaphors for stupid.
Idioms for Stupid
1. Dumb as a doorknob
Meaning: Extremely unintelligent or lacking common sense.
In a Sentence: Despite having clear instructions, he couldn’t figure it out; he’s as dumb as a doorknob.
2. Thick as two short planks
Meaning: Very stupid or intellectually challenged.
In a Sentence: Trying to explain the concept to him was futile; he’s as thick as two short planks.
3. Not the brightest crayon in the box
Meaning: Not very intelligent or lacking in mental acuity.
In a Sentence: Sarah means well, but she’s not the brightest crayon in the box when it comes to solving problems.
4. A few fries short of a Happy Meal
Meaning: Lacking intelligence or common sense.
In a Sentence: John’s idea of fixing the car was a disaster; he’s a few fries short of a Happy Meal.
5. Couldn’t pour water out of a boot with instructions on the heel
Meaning: Utterly incapable of performing even the simplest tasks.
In a Sentence: Watching him try to set up the tent was comical; he couldn’t pour water out of a boot with instructions on the heel.
6. One sandwich short of a picnic
Meaning: Lacking intelligence or rational thinking.
In a Sentence: His conspiracy theories make him seem one sandwich short of a picnic.
7. Not playing with a full deck
Meaning: Not mentally stable or lacking intelligence.
In a Sentence: He keeps believing those wild rumors; it’s clear he’s not playing with a full deck.
8. A few cards shy of a full deck
Meaning: Lacking intelligence or common sense.
In a Sentence: Her decision to quit her job without a backup plan suggests she’s a few cards shy of a full deck.
9. Missing a few screws
Meaning: Lacking intelligence or rationality.
In a Sentence: After hearing his bizarre explanations, it’s clear he’s missing a few screws.
10. All foam, no beer
Meaning: Superficial or appearing smarter than one actually is.
In a Sentence: He talks a big game, but it’s all foam, no beer; he lacks substance.
11. Not the sharpest tool in the shed
Meaning: Lacking intelligence or mental acuity.
In a Sentence: When it comes to solving puzzles, she’s not the sharpest tool in the shed.
12. One brick short of a load
Meaning: Lacking intelligence or rational thinking.
In a Sentence: His bizarre beliefs make him seem one brick short of a load.
13. A few bricks shy of a load
Meaning: Lacking intelligence or common sense.
In a Sentence: Her inability to follow basic instructions suggests she’s a few bricks shy of a load.
14. A few grapes short of a fruit salad
Meaning: Lacking intelligence or rationality.
In a Sentence: His wild theories make him appear a few grapes short of a fruit salad.
15. Two tacos short of a combination plate
Meaning: Not very intelligent or lacking mental acuity.
In a Sentence: Trying to explain the concept to him was like talking to someone two tacos short of a combination plate.
16. Missing the plot
Meaning: Failing to understand or comprehend a situation.
In a Sentence: When it comes to technology, she’s often missing the plot.
17. Not the brightest bulb in the box
Meaning: Lacking intelligence or mental acuity.
In a Sentence: His constant confusion suggests he’s not the brightest bulb in the box.
18. Missing the boat
Meaning: Failing to take advantage of an opportunity or failing to understand something.
In a Sentence: When it comes to investments, he always seems to be missing the boat.
19. One wheel short of a wagon
Meaning: Lacking intelligence or rational thinking.
In a Sentence: Her bizarre actions make her seem one wheel short of a wagon.
20. The lights are on but nobody’s home
Meaning: Someone appears to be present but lacks mental alertness or is not paying attention.
In a Sentence: During the meeting, he was staring blankly; it’s like the lights are on but nobody’s home.
21. Not the sharpest knife in the drawer
Meaning: Lacking intelligence or mental acuity.
In a Sentence: When it comes to solving complex problems, he’s not the sharpest knife in the drawer.
22. A couple of fries short of a Happy Meal
Meaning: Lacking intelligence or rational thinking.
In a Sentence: Her strange choices make her seem a couple of fries short of a Happy Meal.
23. Can’t find their way out of a paper bag
Meaning: Lacking basic navigation skills or problem-solving abilities.
In a Sentence: He struggled with the simplest directions; it’s like he can’t find his way out of a paper bag.
24. One can short of a six-pack
Meaning: Lacking intelligence or rational thinking.
In a Sentence: His constant blunders suggest he’s one can short of a six-pack.
25. Not the swiftest horse in the stable
Meaning: Lacking intelligence or mental acuity.
In a Sentence: When it comes to making decisions, she’s not the swiftest horse in the stable.
26. A few sandwiches short of a picnic
Meaning: Lacking intelligence or rational thinking.
In a Sentence: His strange behavior makes him appear a few sandwiches short of a picnic.
27. A few clowns short of a circus
Meaning: Lacking intelligence or rationality.
In a Sentence: Their bizarre theories make them seem a few clowns short of a circus.
Quizzes About The Idioms in The Article
Quiz 1:
- What does the idiom “Dumb as a doorknob” imply about someone?
a) Extremely intelligent
b) Lacking common sense
c) Highly skilled in problem-solving
Quiz 2:
- What does the idiom “One sandwich short of a picnic” suggest about an individual?
a) They are good at organizing picnics
b) They lack intelligence or rational thinking
c) They have a great sense of humor
Quiz 3:
- If someone is “Missing a few screws,” what does it mean?
a) They are good at home improvement projects
b) They are missing important pieces of information
c) They lack intelligence or rationality
Quiz 4:
- What does the idiom “All foam, no beer” imply about someone?
a) They love beer but can’t find any
b) They have a lot of substance and depth
c) They appear smart but lack substance
Quiz 5:
- If someone is described as “Not the brightest bulb in the box,” what does it mean?
a) They are a great inventor
b) They are not very intelligent
c) They are very creative
Quiz 6:
- What does the idiom “Missing the boat” mean?
a) Not able to locate a boat
b) Failing to understand something or missing an opportunity
c) Going on a vacation by the sea
Quiz 7:
- If someone is “One brick short of a load,” what does it suggest about them?
a) They are a skilled builder
b) They lack intelligence or rational thinking
c) They have a strong work ethic
Quiz 8:
- What does the idiom “Thick as two short planks” mean?
a) Very intelligent and quick-witted
b) Lacking intelligence or intellectually challenged
c) Physically strong but mentally weak
Quiz 9:
- If someone is “Not the swiftest horse in the stable,” what does it imply about their intelligence?
a) They are an excellent equestrian
b) They are not very intelligent or mentally agile
c) They are physically fit but mentally slow
Quiz 10:
- What does the idiom “The lights are on but nobody’s home” suggest about an individual?
a) They have a well-lit house
b) They appear present but lack mental alertness or focus
c) They are always away from home
Answers:
- b) Lacking common sense
- b) They lack intelligence or rational thinking
- c) They lack intelligence or rationality
- c) They appear smart but lack substance
- b) They are not very intelligent
- b) Failing to understand something or missing an opportunity
- b) They lack intelligence or rational thinking
- b) Lacking intelligence or intellectually challenged
- b) They are not very intelligent or mentally agile
- b) They appear present but lack mental alertness or focus
Conclusion
These idioms for stupidity add humor to our language while gently poking fun at situations or individuals who may not always make the wisest decisions. Remember, these expressions are meant to be lighthearted and not offensive.