The story
By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”).
Etymology from Wiktionary, CC BY-SA 4.0.
clam up
Today it means: To become silent; to stop talking. Full definition →
Today it means: To become silent; to stop talking. Full definition →
By analogy with a clam closing itself. Compare clamshell (“mouth”), clam (“mouth”).
Etymology from Wiktionary, CC BY-SA 4.0.