closed books

noun

plural of closed book
as in mysteries
something hard to understand or explain the couple's unorthodox marriage is definitely a closed book to those outside of the relationship

Synonyms & Similar Words

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Example Sentences

Recent Examples of Synonyms for closed books
  1. mysteries
  2. puzzles
  3. secrets
Noun
  • But now, a trail of breadcrumbs strewn across multiple states has led investigators to consider whether the two mysteries have always been intertwined.
    — Lauren Mascarenhas, CNN Money, 24 Oct. 2026
  • But genuinely funny moments are rare, badly outnumbered by done-to-death musings regarding the mysteries of being alive and torturous melodramatic moments in which Klara dully absorbs the severity of Josie’s illness and Chrissy’s sorrow.
    — Los Angeles Times, Los Angeles Times, 22 Oct. 2026
Definition of mysteries
Noun
  • In addition to books, each engagement station features puzzles and toys that help develop motor skills.
    — Rick West, Chicago Tribune, 27 Oct. 2026
  • Players must solve puzzles using the camera to try to break the cycle of madness.
    — Todd Spangler, Variety, 26 Oct. 2026
Definition of puzzles
Noun
  • His new film, which centers on secrets in a renowned vineyard uncovered, slow-burn-style, by a worker and wine critic, aims to land in the $3-$5 million range and potentially attract some even bigger-name talent.
    — Steven Zeitchik, HollywoodReporter, 29 Oct. 2026
  • The Soviet Union, for instance, gained nuclear weapons in part by penetrating the Manhattan Project; more recently, China stole secrets related to the F-22 and F-35 stealth fighter jets and the C-17 cargo plane.
    — Sam Mullins, Foreign Affairs, 28 Oct. 2026
Definition of secrets
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.

Browse Nearby Words

closed book
closed books
closed-captioning
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Cite this Entry

“Closed books.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/closed%20books. Accessed 30 Oct. 2026.

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