# write the book

idiom

Source: https://englishreference.com/idiom/write-the-book
Updated: 2026-08-10

## Meaning

To be an authoritative expert on some specified topic.

## Examples

- If you want to learn about gardening, she basically wrote the book.
- When it comes to fixing vintage cars, my grandfather practically wrote the book on the subject.
- Having spent decades studying the migration patterns of arctic birds, the professor has effectively written the book on the field.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.