Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “open book”

open book

noun uk   us  
be an open book If someone is an open book, it is easy to know what they are thinking and feeling.
(Definition of open book from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of open book?
Browse related topics

You are looking at an entry to do with Easy to understand, but you might be interested in these topics from the Knowing and understanding topic area:

Add Cambridge dictionaries to your browser to your website

Translations of “open book”

Word of the Day

give the green light to sth

to give permission for someone to do something or for something to happen

Word of the Day

Highly delighted, bitterly disappointed, ridiculously cheap: adverbs for emphasis.

by Liz Walter,
October 22, 2014
We often make adjectives stronger by putting an adverb in front of them. The most common ones are very and, for a stronger meaning, extremely: He was very pleased. The ship is extremely large. However, we don’t use very or extremely for adjectives that already have a strong meaning, for example fantastic,

Read More 

life tracking noun

October 20, 2014
the use of one or more devices or apps to monitor health, exercise, how time is spent, etc.

Read More