Today's expression is heads up, meaning a briefing or short announcement - "pay attention, I have something to say." I remember exactly when I encountered this expression - someone used it as if everyone knew exactly what it meant, and I didn't. And why has it just suddently started to be almost universally used? And is it a runtogether, or does it take a hyphen, or not?
Interestingly, it is featured in the ABC News Radio word pages. They point out that the US meaning is quite different, referring to being alert and watchful. As you can see from a search of the word, its use has become very diffuse. In New Zealand the Labour Party has the domain name; for the .com domain it is an online music store; in .co.uk a neurological physiotherapy practice has the name, and in Germany its about motor sports. Meanwhile in Tuvalu, the headsup domain name goes to . . . roar, a US advertising site.