We found 8 dictionaries that define the word an open book:

General (7 matching dictionaries)

1. an open book: Merriam-Webster
2. an open book: Oxford Learner's Dictionaries
3. an open book: Collins English Dictionary
4. An Open Book (poetry collection): Wikipedia, the Free Encyclopedia
5. an open book: Merriam-Webster

Miscellaneous (1 matching dictionary)

6. an open book: Idioms

Opposite: mystery, secret, enigma Phrases: read him like an open book, more... ▸ Words similar to an open book ▸ Usage examples for an open book ▸ Idioms related to an open book ▸ Wikipedia articles (New!) ▸ Words that often appear near an open book ▸ Rhymes of an open book ▸ Invented words related to an open book