Meaning
Someone who tends to reveal secrets or talk too much without discretion.
Cultural Background
In Korea, the concept of 'Che-myeon' (face) is vital. If you are labeled as '입이 싸다', you lose social standing because you are seen as someone who cannot protect the 'face' of others. Confucian values emphasize 'Shin' {信|신} (trust). A 'cheap mouth' directly violates the principle of being a 'Gun-ja' {君子|군자} (a person of noble character) who speaks little but acts much. The 'blabbermouth' is a staple character in K-dramas, often used to move the plot forward by leaking a secret at the worst possible moment. In the hierarchical Korean workplace, having a 'cheap mouth' about a superior's private life is a fast track to being fired or sidelined.
Use with '진짜'
Adding '진짜' (really) or '너무' (too) makes the criticism feel more natural: '입이 진짜 싸다'.
Don't use for 'Honesty'
If someone is just honest, use '솔직하다'. '입이 싸다' is always negative.
Meaning
Someone who tends to reveal secrets or talk too much without discretion.
Use with '진짜'
Adding '진짜' (really) or '너무' (too) makes the criticism feel more natural: '입이 진짜 싸다'.
Don't use for 'Honesty'
If someone is just honest, use '솔직하다'. '입이 싸다' is always negative.
The 'Light' Alternative
If you want to sound more sophisticated and less aggressive, use '입이 가볍다' instead.
The Heavy Mouth
Always aim to be described as '입이 무겁다' in a Korean company; it's a key to promotion.
Test Yourself
Choose the correct word to complete the sentence about a gossip.
민수는 비밀을 못 지켜요. 정말 입이 ( ).
'입이 싸다' is the set idiom for someone who cannot keep secrets.
Fill in the blank with the correct particle.
그 친구는 입( ) 싸서 조심해야 돼.
In this idiom, '입' (mouth) is the subject of the adjective '싸다', so the subject marker '이' is used.
Match the idiom with its meaning.
Match the following:
These are all common '입' idioms with very different meanings.
Complete the dialogue naturally.
A: 지민이한테 내 비밀 말했어? B: 아니, 걔는 ( ) 절대 말 안 했지.
The context implies B didn't tell Jimin because Jimin has a big mouth (입이 싸서).
🎉 Score: /4
Visual Learning Aids
Mouth Weight vs. Value
Common '입' Idioms
Personality
- • 입이 싸다
- • 입이 무겁다
- • 입이 짧다
Actions
- • 입을 맞추다
- • 입을 모으다
- • 입을 씻다
Practice Bank
4 exercises민수는 비밀을 못 지켜요. 정말 입이 ( ).
'입이 싸다' is the set idiom for someone who cannot keep secrets.
그 친구는 입( ) 싸서 조심해야 돼.
In this idiom, '입' (mouth) is the subject of the adjective '싸다', so the subject marker '이' is used.
Match each item on the left with its pair on the right:
These are all common '입' idioms with very different meanings.
A: 지민이한테 내 비밀 말했어? B: 아니, 걔는 ( ) 절대 말 안 했지.
The context implies B didn't tell Jimin because Jimin has a big mouth (입이 싸서).
🎉 Score: /4
Frequently Asked Questions
10 questionsYes, it is a negative description of someone's character. It implies they are untrustworthy.
Only as a joke or a confession of a fault, e.g., '제가 입이 좀 싸서 걱정이에요.'
'싸다' feels more judgmental and implies the words have no value. '가볍다' is the standard way to say someone can't keep a secret.
No, it is too informal and emotional. Use '보안이 철저하지 못하다' (Security/confidentiality is not thorough).
Mostly, but it can also apply to someone who gossips about trivial things constantly.
There is no 'polite' way to call someone a blabbermouth, but you can use '말씀이 좀 많으신 편이에요' (They tend to talk a bit much).
You can say '입 무겁게 해줘' (Keep your mouth heavy) or '비밀로 해줘'.
It is used for anyone, though historically it appeared often in tropes about neighborhood women.
This is not a standard idiom, but people might use it to mean someone rarely speaks or their words are 'expensive' (valuable).
Yes, if a child tells a surprise secret, you might say '입이 싸네~' in a playful way.
Related Phrases
입이 무겁다
contrastTo be good at keeping secrets.
입이 가볍다
synonymTo have a light mouth.
입에 침이 마르다
similarTo talk about something so much your spit dries up.
입을 맞추다
builds onTo coordinate stories/lies.
입이 짧다
confusingTo be a picky eater.
