closed book
Americannoun
noun
-
something deemed unknown or incapable of being understood
-
a matter that has been finally concluded and admits of no further consideration
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.
That is certainly the case in France, where the foreign intentions of Britain's likely next PM seem like a closed book.
From BBC ● Jul. 12, 2026
“As you know, I’m not normally a closed book on this stuff,” Sean told me.
From Washington Post ● Apr. 26, 2023
When she was growing up, Xie said, stories about this era were a closed book.
From New York Times ● Sep. 19, 2022
A lot of the stuff we know as fact turns out to be closed book fiction, a version of the truth steeped in the memory and settled now as a matter of certainty.
From The Guardian ● Apr. 26, 2020
Dustfinger’s face was a closed book, and Meggie had the feeling that if anyone tried reading it he would rap their knuckles.
From "Inkheart" by Cornelia Funke
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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.