clam up

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

Definition

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

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

simple

“He always clams up when I ask about his family.”

contextual

“The witness clammed up as soon as the police started asking about the night of the robbery.”

complex

“Despite being normally talkative, the CEO clammed up during the press conference when reporters questioned the company's recent financial losses.”

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

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

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.

By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

shut upgo silentfreeze

open upconfide

Particles

up

Separability

inseparable

Pattern

clam + up

go quietshut upfreeze upgo silent