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closed book

closed book

1 7.4
Something that is hard to understand or know much about
  • noun
  • /kloʊzd bʊk/
  • Informal
translation icon : un libro cerrado
  • This protagonist remains almost a completely closed book.

And memory is just a hand on a closed book that believes, because it must believe that that's how you read.

Examples

  • While Obama is a closed book.

    Blog text (18)
  • To me, the topic of quantum physics is a closed book that I find difficult to comprehend.

  • But you are a closed book to her.

    Fiction book (1991)
  • And memory is just a hand on a closed book that believes, because it must believe that that's how you read.

  • That keeps the mantin matter a closed book.

  • It's not necessarily a totally closed book, but it is worth understanding the facilitative and debilitative ways of tracking.

  • His feelings about the situation are a closed book to everyone around him.

  • After years of silence, her past remains a closed book that few understand.

Synonyms

mystery
vsclosed book
660 4.7

Something that is hard to understand or explain

can also mean a topic not known about or no longer considered
secret
vsclosed book
375 3.9

A thing people do not understand yet

is broader, applying to difficult or unfamiliar subjects beyond hidden facts
enigma
vsclosed book
33 8.1

A person or thing that is mysterious and hard to understand

is used more generally for unknown topics or things no longer considered

Antonyms

1.0

Easy to understand and not confusing

open book
  • Informal
12 3.5

A person whose feelings and thoughts are easy to understand

How Understandable

open book
  • Informal
12 3.5
closed book
  • Informal
1 7.4
mystery
660 4.7
enigma
33 8.1

Surface Forms

closed book singular
closed books plural

Morphology

closed + book

The literal combination 'closed' (shut) + 'book' (a readable object) transparently evokes inaccessibility or unreadability, so a learner could infer that something is not open to inspection. However, extending that image to mean a person or subject is difficult to understand is a metaphorical shift (person-as-book) that is not fully predictable without exposure, so it is only partially transparent.

Etymology

The noun closed book comes from the simple image of a book with its cover shut so you cannot read it. So, if a person or subject is a closed book, they are 'difficult to understand' or 'not known' to others.