watch (someone's) back(redirected from watch her back)
watch (someone's) back
To be willing and prepared to help or defend someone; to look out for someone in case they need assistance. Don't worry about those thugs, buddy. I'll watch your back if they ever come bother you again. You can always rely on your parents to watch your back.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
watch your (or someone's) backprotect yourself (or someone else) against danger from an unexpected quarter.
Farlex Partner Idioms Dictionary © Farlex 2017