Phrase guide

open book

noun · 4 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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  • Australia: Recorded audio is listed in the source snapshot.

1

noun

Meaning 1

Something whose salient aspects are obvious or easily interpreted.

Definition source: English Wiktionary via Wiktextract

Usage: idiomatic

Examples

  • 2009, May 21, Barack Obama, speech, Protecting Our Security and Our Values But I have never argued – and never will – that our most sensitive national security matters should be an open book.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

A person who responds candidly to questions or openly displays their emotions or intentions.

Definition source: English Wiktionary via Wiktextract

Usage: idiomatic

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

3

noun

Meaning 3

An open book decomposition.

Definition source: English Wiktionary via Wiktextract

Topics: mathematics, sciences, topology

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

4

noun

Meaning 4

An inside angle in the rock.

Definition source: English Wiktionary via Wiktextract

Topics: climbing, hobbies, lifestyle, sports

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

No etymology was provided for this word.

Across languages

Translations

23 source translations are retained for this English entry.

  • Chinese Mandarin: 一目瞭然的事物 /一目了然的事物 (yīmùliǎorán de shìwù) — thing easily interpreted
  • Finnish: avoin kirja — thing easily interpreted
  • French: livre ouvert — thing easily interpreted
  • German: offenes Buch — thing easily interpreted
  • Hungarian: nyitott könyv — thing easily interpreted
  • Italian: libro aperto — thing easily interpreted
  • Polish: oczywistość — thing easily interpreted
  • Portuguese: livro aberto — thing easily interpreted
  • Russian: откры́тая кни́га (otkrýtaja kníga) — thing easily interpreted
  • Spanish: libro abierto — thing easily interpreted
  • Chinese Mandarin: 易於了解的人 /易于了解的人 (yìyú liǎojiě de rén) — person who is honest or open
  • Chinese Mandarin: 胸無城府的人 /胸无城府的人 (xiōngwúchéngfǔ de rén) — person who is honest or open
  • Dutch: open boek — person who is honest or open
  • Finnish: avoin kirja — person who is honest or open
  • French: ravi de la crèche — person who is honest or open
  • German: offenes Buch — person who is honest or open
  • Italian: libro aperto — person who is honest or open
  • Polish: naiwniak — person who is honest or open
  • Polish: naiwniaczka — person who is honest or open
  • Portuguese: livro aberto — person who is honest or open
  • Russian: откры́тая кни́га (otkrýtaja kníga) — person who is honest or open
  • Russian: на лбу́ напи́сано (na lbú napísano) — person who is honest or open
  • Spanish: libro abierto — person who is honest or open