heads up(redirected from heads-up)
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1. An interjection used as a warning for any imminent danger. "Heads up!" he shouted as the brick fell off the edge of the building. Heads up, the boss is looking for you and she looks angry!
2. noun A preliminary notice, especially of future difficulty, trouble, or danger; a warning. Often hyphenated. Make sure everyone gets the heads-up about the inspection tomorrow morning. We don't want anyone coming in unprepared. Hey, just a heads-up—the boss is in a foul mood, so don't do anything to attract attention to yourself! Just give me a heads-up if you need a ride.
look up because something may hit you
Usage notes: often shouted as a warning: Heads up! Watch out for the baseball!
A warning to watch out for potential danger, as in Heads up, that tree is coming down now! The expression is generally in the form of an interjection. [c. 1940]