Heads up is an interjection used when you need to warn someone to look out. A heads-up is the actual warning you gave the individual. This is commonly used in the phrase giving someone a heads-up. While the correct spelling includes the hyphen, actual usage suggests that it will become obsolete some day.
Heads-up can also be used as an adjective to describe a person as being cautious or aware of surroundings. Keeping one’s head up means to be watchful.
Be aware that the verb head can also mean to lead, so to say, “She heads up the project” means that she directs the project.
A head-up display is a gauge or reading which does not require the pilot or driver to lower his or her eyes. It can also be called a heads-up display.
A related term is head up which is used in sailing to mean steer into the wind.
The committee approved the campaign, applauding in particular the slogan “Heads up, Halifax!” – a “call to action” that DeBaie said is universal and high-impact. [Metro News]
“[W]e can give all the folks that we gave a heads-up to a day or two earlier, we can say OK, it’s worse than we expected, it’s as expected, or maybe it’s a bit of a dud and is not going to be the impact we thought it might have here on Earth,” William Murtagh, program coordination at the Space Weather Prediction Center, told Voice of America. [International Business Times]
Philly Brown made a heads-up play on a strange turn of events on a punt return against the Chicago Bears. [Yahoo Sports]
Hardware startup Navdy has raised a $6.5 million seed funding round for its connected car tech, which focuses on the heads-up display it created. [Tech Crunch]