Thesaurus results for CLOSED BOOKS

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

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Noun

One of the biggest mysteries has been his extreme home/road splits.

— Maddie Lee, Los Angeles Times, 19 Aug. 2026
Now researchers are using advanced imaging technology to look at the narwhal’s tusk in unprecedented detail—studying it in the hope of unraveling some of its mysteries.

— Jackie Flynn Mogensen, Scientific American, 18 Aug. 2026

Definition of mysteries

Noun

Learning new skills, playing word games and having stimulating hobbies like reading or puzzles keeps the mind sharp.

— Helen Carefoot, Flow Space, 14 Aug. 2026
Players can take control of enemies and use their abilities to explore, fight, and solve puzzles, while the creature’s biology changes the world in response to their actions.

— Matt Gardner, Forbes.com, 12 Aug. 2026

Definition of puzzles

Noun

As China’s strategic rivalry with the US and its allies deepens, Beijing has broadened its anti-espionage campaign, casting suspicious eyes on foreign ties amid concerns about the leak of state secrets.

— Sylvie Zhuang, CNN Money, 16 Aug. 2026
This inner corona is already giving up its secrets to Proba-3.

— Jamie Carter, Forbes.com, 15 Aug. 2026

Definition of secrets

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“Closed books.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/closed%20books. Accessed 21 Aug. 2026.

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noun

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