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Showing results for closed book. Search instead for closed+book.
Synonyms

closed book

American  

noun

  1. something that is not known or cannot be understood; a mystery or puzzle.

    Abstract art is a closed book as far as I'm concerned.
closed book British  

noun

  1. something deemed unknown or incapable of being understood

  2. a matter that has been finally concluded and admits of no further consideration

"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

Etymology

Origin of closed book

First recorded in 1910–15

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

“As you know, I’m not normally a closed book on this stuff,” Sean told me.

From Washington Post • Apr. 26, 2023

When the bank collapsed, her loan was one of thousands sold by the government to so-called "closed book" lenders.

From BBC • Mar. 1, 2023

When she was growing up, Xie said, stories about this era were a closed book.

From New York Times • Sep. 19, 2022

And also Keeley didn’t think about that she had hurt Roy, because Roy’s a closed book.

From Los Angeles Times • Aug. 24, 2021

I'd glance at her occasionally, but that girl is a closed book.

From "From Twinkle, with Love" by Sandhya Menon

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

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