An open book

Idiom

An open book

Definition

An idiom used to describe someone who is very transparent and easy to understand. It implies that their thoughts and feelings are clearly visible and they can be easily read.

Examples

She’s an open book; you can always tell what she’s thinking.

He’s so easy to read – it’s like he’s an open book.

I don’t need to ask her how she’s feeling; she’s an open book.

He never hides his feelings – he’s an open book.

She’s a total open book; everyone knows all her secrets.

Origin

The origin of this phrase is uncertain, but it is thought to have originated in the late 19th century.

FAQs

What does it mean when someone is an open book?

It means that the person is very transparent and easy to understand; their thoughts and feelings are clearly visible.

What is the origin of the idiom ‘An open book’

The origin of this phrase is uncertain, but it is thought to have originated in the late 19th century.