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

Relevance

Example Sentences

Recent Examples of Synonyms for closed books
  1. mysteries
  2. puzzles
  3. secrets
Noun
  • Just bearing witness to the marketing for all these murder-mysteries is enough to make any discerning viewer desperate for Hollywood to hurry up and start chasing the next trend already.
    — Ben Travers, IndieWire, 29 July 2026
  • The anime merely depicts a border spat between a few small nations, whereas the manga is more global in reach and also deals with much of the underlying mysteries of the corrupted world the characters now live in.
    — Ollie Barder, Forbes.com, 29 July 2026
Definition of mysteries
Noun
  • Players navigate impossible architecture and perspective-bending puzzles as reality twists around them.
    — Destiny Jackson, Deadline, 23 July 2026
  • The lowest score came from The Guardian, which handed it two stars out of five, while Giant Bomb landed positive overall with a complaint that the boss fights lean on damage sponges more than puzzles.
    — Brian Mazique, Forbes.com, 22 July 2026
Definition of puzzles
Noun
  • Over the course of the weekend, secrets are revealed, including that Chan’s character Gigi had been having an affair with Hollis’ husband Matthew.
    — Leigh Nordstrom, Footwear News, 24 July 2026
  • After making Comic-Con history for debuting Spider-Man 2, the first video game to ever occupy Hall H, Insomniac Games and Sony Interactive clawed their way back to San Diego on Thursday to reveal gameplay secrets for the upcoming Marvel’s Wolverine.
    — Destiny Jackson, Deadline, 23 July 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
See all Nearby Words

Cite this Entry

“Closed books.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/closed%20books. Accessed 31 Jul. 2026.

Copy Citation
Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

More from Merriam-Webster

Word of the Day

Listen to the pronunciation of comely

See Definitions and Examples »

Popular in Grammar & Usage

See More

7 Pairs of Commonly Confused Words

Merriam-Webster’s Great Big List of Words You Love to Hate

Is it 'nerve-racking' or 'nerve-wracking'?

Why does English have so many silent letters?

Your vs. You're: How to Use Them Correctly
See More

Popular in Wordplay

See More

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

The Words of the Week - Jul. 31

Even More Bird Names that Sound Like Insults (and Sometimes Are)
See More

Popular

See More

7 Pairs of Commonly Confused Words

Dutch Treat and French Leave: Eight Place-Based Compounds

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
asap street sign
Figure Out These Acronyms ASAP You don't have to be a NASA engineer to get these...
See All