# clam up

Source: https://englishreference.com/word/clam-up
Updated: 2026-08-27

## Senses

### 1. to stop talking

phrasal verb · CEFR B2 · Informal

to suddenly stop speaking or refuse to answer questions, often because you are nervous or want to keep a secret.

For teachers: to refuse to speak or provide information; to become suddenly silent, especially when under pressure or in a social situation.

- The witness clammed up as soon as the lawyers started asking about the money.
- Despite the investigator's persistent questioning, the suspect clammed up and refused to provide any further details regarding his whereabouts.

Usage: This phrasal verb is intransitive and does not take a direct object.

Teaching tip: The metaphor refers to a clam closing its shell tightly when it feels threatened. It is very common in crime dramas or when discussing shy people.

## Examples

- He always clams up when I ask about his family.
- The witness clammed up as soon as the police started asking about the night of the robbery.
- Despite being normally talkative, the CEO clammed up during the press conference when reporters questioned the company's recent financial losses.

## Usage notes

- Teaching tip: use the image of a clam closing its shell tightly to help students remember the meaning of 'shutting' one's mouth.

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