From Longman Dictionary of Contemporary Englishin my bookin my bookTHINK/HAVE THE OPINION THAT spoken said when giving your opinion In my book, nothing is more important than football. → book
Examples from the Corpus
in my book• C., in my book, is U. S. Sen.• These stages are described in more detail in my books First Feelings and Playground Politics.• I put this down in my book.• Which is just ducky, in my book.• So I put everything in my book, such-and-such-a-thing, such-and-such-a-thing.• During his stay he took much interest in my books and asked to borrow one.• But they accuse me of lying in my book.• So I went on until just after refreshment time: Spoke to Mr so-and-so - lots of things in my book.• Well, in my book, if you steal, you deserve to get caught. 