behind you!

behind you!

Watch out! A warning shouted in times of danger or to indicate one's presence behind someone. I yelled, "Behind you!" as soon as I saw the masked man reach for the unsuspecting woman's purse. All chefs know to say "behind you" when they're passing other chefs on the line.
See also: behind
Farlex Dictionary of Idioms.

Behind you!

Look behind you!; There is danger behind you! "Behind you!" shouted Tom just as a car raced past and nearly knocked Mary over. Alice shouted, "Behind you!" just as the pickpocket made off with Fred's wallet.
See also: behind
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

Behind you!

phr. Look behind you!; There is danger behind you! (see also check your six, on your six.) “Behind you!” shouted Tom just as a car raced past and nearly knocked Mary over.
See also: behind
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • run behind
  • on (one's) six
  • on your six
  • drop behind
  • get behind
  • get behind (someone or something)
  • get behind someone/something
  • get behind something
  • lie behind
  • lie behind (someone or something)
References in classic literature
You walk ahead and I'll walk immediately behind you! I won't leave you by a step!"