Watch out for danger behind your back (like you might get jumped or something).

Watch your back.

Keep an extra set of eyes on the back of your head.
Dude, be careful man. Watch your six.
by Brent Ninja October 11, 2012
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Watch your back.
Keep an eye on what could be behind you.
Turn around and look.
by K!ngFox July 10, 2021
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Military term for watching/covering your back/rear side
Stay frosty and cover/watch your six!
by gunshy77 May 11, 2014
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