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
Relevance
Example Sentences
Recent Examples of Synonyms for closed books
Noun
-
Easily recognizable by her orange turtleneck and thick-rimmed glasses, Velma is known for her quick wit, keen eye for detail and ability to solve even the trickiest mysteries.—
Samantha Stutsman,
PEOPLE,
14 June 2026 -
Neurological mysteries, immaculate conception, exposure therapy, a natural-birth cult (cults!—
Sara Holdren,
Vulture,
14 June 2026
Noun
-
Check out the all new PLAY hub with puzzles, games and more!—
Daryl Austin,
USA Today,
18 June 2026
-
To test that, the final group completed cognitively demanding games such as mazes and shape puzzles called tangrams that contained no academic content.—
Supreet Kaur,
Scientific American,
10 June 2026
Noun
-
Critical information including intellectual property, military intelligence, medical records, and government secrets may be in danger.—
Chuck Brooks,
Forbes.com,
13 June 2026
-
But when one of them is murdered, private investigator Aubrey Merritt and her assistant Olivia Blunt must unravel decades of secrets and fractured loyalties to uncover the killer.—
Kait Hanson,
Southern Living,
13 June 2026
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.
Cite this Entry
“Closed books.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/closed%20books. Accessed 19 Jun. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
