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
  • Starring Zhang Yi, Ma Li, and Chen Minghao alongside guest appearances by Karry Wang, Fan Chengcheng, and Chen Feiyu, the multi-decade drama chronicles an elite public security detective unravelling major criminal mysteries based on real cases.
    — Naman Ramachandran, Variety, 19 Oct. 2026
  • Most Sherlock Holmes stories are mysteries – intricate, complex and brilliantly written.
    — Jesse Whittock, Deadline, 16 Oct. 2026
Definition of mysteries
Noun
  • Here’s a prime example of a more cryptic style of clue that sometimes pops up in late-week puzzles.
    — Sean McGowan, New York Times, 22 Oct. 2026
  • Dropbox has introduced memory exercises, attention-span training, and puzzles.
    — Emma Burleigh, Fortune, 19 Oct. 2026
Definition of puzzles
Noun
  • State secrets, exposed Curiously, the grand jury indicted no one, saying no one seemed to know who was responsible.
    — Sun Sentinel Editorial Board, Sun Sentinel, 22 Oct. 2026
  • One of the secrets to SunZia’s ultimate success in New Mexico was the project’s ability to strike compromises, even with some of its earliest critics.
    — Sara Herschander, Vox, 22 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 24 Oct. 2026.

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