Q: I’m interested in learning more about the phrase “heads up,” as in “I will give you a heads up when the contract is signed.” Does it have an origin older than the current corporate use?
A: The short answer is yes, but the longer one is more interesting. So let’s begin at the beginning – a couple of centuries ago.
The expression “heads up,” used as an interjection meaning “straighten up” or “hold your head up,” dates back to the early 19th century, according to the Oxford English Dictionary.
It was first used in this sense, as far as we know, in the English novelist Maria Edgeworth’s short play The Knapsack (1801): “They marched, and I amongst them, to face the enemy – heads up – step firm – thus it was – quick time – march!”
Since the early 20th century, the expression has been used in the United States as an adjectival phrase, meaning alert or in the know, according to the OED.
The dictionary’s first adjectival citation is from a 1913 article in the New Smyrna (Florida) News: “He was always right on the job, and looking ‘heads up.’ “
The Random House Historical Dictionary of American Slang has an earlier adjectival usage, from William A. Caruthers’s book The Kentuckian in New York (1834): “There I sat with my feet drawn straight under my knees, heads up, and hands laid close along my legs, like a new recruit on drill.”
In this sense, Random House says, the expression is probably a literal one: a wide-awake, alert person holds his head erect rather than falling asleep and nodding.
Now, on to your question about the current use of “heads up” as a noun meaning a warning. This, it turns out, is of much more recent vintage.
The OED cites a 1981 example from the Associated Press: “When that data is provided … it is regarded as being a heads-up on a sale.”
A bit earlier, in 1979, the Washington Post used the longer phrase “heads-up alert” to describe a warning by intelligence officials about unauthorized diplomatic contacts.