Dictionary and Thesaurus

Definition of Clam Up

• (verb) refuse to talk or stop talking; fall silent; "The children shut up when their father approached"

Synonyms of Clam Up

• Close Up
• Dummy Up
• Shut Up
• Belt Up
• Button Up
• Be Quiet
• Keep Mum

Antonyms of Clam Up

• Open Up

Homophones of Clam Up