clam up


verb

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

QUIZZES

BECOME A PRO CHEF WITH THIS EXQUISITE CUISINE QUIZ!

Even if you can't be a professional chef, you can at least talk like one with this vocabulary quiz.
Question 1 of 9
You may have read the word "simmer" in a recipe or two, but what does it really mean?
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Idioms and Phrases with clam up

clam up

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]

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.