on your six

on (one's) six

Directly behind someone. Sometimes used as an imperative to look behind one. A reference to the numbers on the face of a clock, with 12 being the direction one is looking. Someone provide cover fire, there are snipers on our six! On your six, Tom—Mary's here, and she looks angry.
See also: on, six
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

on your six

phr. [look] behind you. ) (see also Behind you!.) Look out! On your six!
See also: on, six
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.
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