in somebody's book

in (one's) book

According to one's opinion, judgment, or values. In my book, it's worse to run away from a fight than to start one. You kissed a girl, even though you have a girlfriend. That's cheating in my book, dude. You proved you can handle yourself in a scrap. You're OK in my book, kid.
See also: book
Farlex Dictionary of Idioms.

in somebody’s book

(spoken) in somebody’s opinion; according to somebody’s judgement: They took the car away without asking me, and in my book that’s theft.
See also: book
Farlex Partner Idioms Dictionary
See also:
  • in (one's) book
  • in book
  • in my book
  • in one's book
  • in your book
  • (one's) bark is worse than (one's) bite
  • kiss (one) on (some place)
  • kiss on
  • at the end of (one's) fingertips
  • thrust away from