Translation guide
Describes someone who is unwilling to speak, either because they are angry, determined, or secretive. The most natural Japanese expressions depend on the nuance: physical tightness of the mouth, emotional silence, or refusal to reveal information.
The person is silent because they are angry, stubborn, or resolute, often with a closed mouth.
He kept his mouth tightly shut and said nothing.
Means 'silent' or 'without words'. Can describe a tight-lipped attitude when combined with verbs like 押し通す (to persist).
She remained tight-lipped the whole time.
To fall silent and refuse to speak, often with a stubborn or heavy atmosphere. Implies a deliberate silence.
He sat tight-lipped, staring out the window.
The person is unwilling to share details, often in a situation like an interview or interrogation.
Literally 'mouth is hard'. A common idiom meaning someone is tight-lipped or discreet, good at keeping secrets.
He's tight-lipped, so it's safe to tell him secrets.
Means 'won't say anything at all'. Used when someone completely refuses to comment, often in formal or news contexts.
Formal/legal term for 'remain silent' or 'refuse to answer'. Used in official contexts like police questioning.
The suspect exercised the right to remain silent.
Describing the actual appearance of lips pressed together, often from tension or anger.
口が固い describes a person's character (discreet, trustworthy). 口を固く結ぶ describes a temporary action or state (refusing to speak now).
He is tight-lipped (by nature).
He clamped his mouth shut (at that moment).
The police were tight-lipped about the incident.