clam
nounUK /klæm/
US /klæm/
A clam is a small sea animal with a hard shell that lives in the sand.
We found a clam on the beach and watched it dig into the wet sand.
OTHER MEANINGS
2. A shy person who does not talk much.
He clammed up when the teacher asked him to speak.
3. To shut tightly or refuse to speak.
She clammed up as soon as the reporters arrived.
4. A dollar, in old slang.
He paid five clams for the old book.