watch your back

Also found in: Acronyms, Wikipedia.

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.
See also: back, watch

watch your (or someone's) back

protect yourself (or someone else) against danger from an unexpected quarter.
See also: back, watch
References in periodicals archive ?
She added: 'Staff were saying watch your back because Anna's been called up to, senior manager Gaynor Flay's office to make a complaint.
Vastly Improved Artificial Intelligence (AI): Watch your back as rebels send their own team members to flank your position or gain vantage points by utilizing vertical gameplay to pick you off from the rooftops above.
But yesterday, her partner Nick Kroll jokingly posted on Twitter: "Hey Bono, watch your back.
ONE TO WATCH: Watch Your Back (left) is Garry's nap at Ayr
As you stroll through Sleepy Hallow, but careful now and watch your back.
The singer claims his message collection includes one that warns, `You better watch your back, because you are seriously f***.
Good luck out there, take care of yourselves and each other and always, always watch your back - Carlos''
Her co-star, Sam Waterson, adds that even in real life, "Angie would be a great person to have watch your back in a fight.
WATCH your back Gameboy, another new handheld device is after your gaming crown.
Better watch your back Joni, no-one messes with the big 'M'.