closed book

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closed book

noun closed books

  1. idiomatic A person or thing that cannot be easily understood; someone or something incomprehensible or puzzling. Her courteous, sedate, inexorable husband, whose will she could not bend, whom she could not cajole, whose mind was a closed book to her — a book which had lain by her hand for three years, which she had never had the curiosity to open!

Opposite: open book

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noun

Opposite: open book

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MLA

"closed book." Wiktionary, via Micwyn, micwyn.com/word/closed%20book. Accessed 6 Nov. 2026.

APA

closed book. (n.d.). In Wiktionary, via Micwyn. Retrieved November 6, 2026, from https://micwyn.com/word/closed%20book

Chicago

"closed book." Wiktionary, via Micwyn. Accessed November 6, 2026. https://micwyn.com/word/closed%20book.

BibTeX
@misc{closed_book_2026,
  title = {closed book},
  howpublished = {Wiktionary, via Micwyn},
  year = {2026},
  url = {https://micwyn.com/word/closed%20book},
  urldate = {2026-11-06}
}