Watching out.. keepin an eye out.

Watching behind .. someones watching your back in the 6 O'clock position
Keepin Six is used in jail and in the Military.

In jail it means that your keepin an eye out for the six which is a word used for Correctional Officers.

In the military 6 is the bottom of the clock. Your looking at the 12 o'clock position so the 6 o'clock position is behind you
by C.Ontario August 3, 2008
Get the Keepin Six mug.