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closed book

SEE SYNONYMS FOR closed book

noun

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.

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Question 1 of 9
You may have read the word "simmer" in a recipe or two, but what does it really mean?
To cook in water that begins cold and then reaches a boil.
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Origin of closed book

First recorded in 1910–15

Words nearby closed book

close company, close corporation, close-cropped, closed, closed anesthesia, closed book, closed-captioned, closed chain, closed chain compound, closed chest massage, closed circuit
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Words related to closed book

riddle, conundrum, subtlety, question, enigma, secrecy, problem, thriller, mystery, dilemma, puzzle, quandary, complexity, teaser, puzzlement, mystification, perplexity, stickler, cliffhanger, twister

British Dictionary definitions for closed book

closed book

noun

something deemed unknown or incapable of being understood
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