in one's book

Meanings

prepositional phrase

informalIn one's opinion.
Clara did nothing wrong in my book.
5 more examples
Near-synonyms: in one's view, in one's eyes, to one's mind; see also Thesaurus:in my opinion
In my book, there's nothing wrong with that.
In his book, that counts as an affront, for some reason.
Is this "the field?" Not in our book, it isn't.
1973, QST, volume 57, number 2, page 87
[Jeffcoat:] I'll qualify that in a moment, but in my book I think when it comes to sheer professionalism, there's nothing quite like an American broadcaster.
1975 February 8, Kevin O'Donohue, Stan Clark, Brian McClenaughan, Frank Jeffcoat, “Four Broadcasters Compare U.S. Radio with Australian Radio - The Knockout Blow”, in Billboard, page A-7
Synonyms: in someone's view, in someone's eyes, to one's mind
Used other than figuratively or idiomatically: see in, one's, book.
Today's homework is in your book. Could I borrow it?

prepositional phraseIn one's opinion.

Also see

Refers to a notional book or list of one's opinions and beliefs. Slang from the mid-1900s.

Cite this entry

APA

in one's book. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/in%20one's%20book

MLA

“in one's book.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/in%20one's%20book. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “in one's book,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/in%20one's%20book.