check (one's) six

check (one's) six

To look behind oneself, typically by looking over one's shoulder. "Six o'clock" is a military term referring to the area behind oneself. Make sure to check your six, in case someone tries to follow you.
See also: check, six
Farlex Dictionary of Idioms.

check your six

tv. look behind you (where there may be danger). (see also on your six. Refers to six o’clock as being behind one, as if one were facing twelve o’clock.) Check your six, bud. Some gangsta’s getting close to your wallet.
See also: check, six
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • check your six
  • watch (one's) six
  • get behind
  • get behind (someone or something)
  • get behind someone/something
  • get behind something
  • take cover
  • hide behind
  • hide behind (someone or something)
  • drop out of sight