clam up

verb

1. informal,  (intr, adverb) to keep or become silent or withhold information

Idioms and Phrases

Refuse to talk or respond, as in Whenever she asks her teenager about his activities, he clams up. This term alludes to the tightly closed valves of a live clam. [Slang; early 1900s]

Example Sentences

However, he clammed up when Welker asked him to share other methods in which he might stay on.

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Another factor is “just having extreme social anxiety for a long, long time. People were fascinating to me, but also scary. I would kind of clam up around people because my brain would short-circuit.”

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As a nation, we are so “clammed up” about death, illness and mental health, says Alison, that it is a stigma that Parys died from an accidental drug overdose.

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“What kind of helpful information would be in books about a wannabe Chosen One who clams up when it’s time to stop the bad guy?”

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“But as soon as we turned our microphones on and stuck them in their faces, they totally clammed up.”

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Related Words

• allay 
• appease 
• assuage 
• hush 
• mollify 
• muffle 
• muzzle 
• pacify 
• please 
• relax 
• satisfy 
• soften 
• soothe 
• squelch 
• subdue