know someone or something inside out

know (someone or something) inside out

To know everything or nearly about someone or something; to be thoroughly familiar with someone or something. I've read this book so many times that I know it inside out. If you study this material for weeks, you'll know it inside out by the test date. I just think you should know a person inside out before you decide to marry them.
See also: inside, know, out
Farlex Dictionary of Idioms.

know someone or something inside out

know someone or something very thoroughly.
See also: inside, know, out, someone, something
Farlex Partner Idioms Dictionary
See also:
  • know (someone or something) inside out
  • know inside out
  • know somebody/something inside out
  • know something/someone inside out
  • know only too well
  • a closed book
  • closed book, a
  • know (something) in (one's) bones
  • I know
  • Adam's off ox