the.com/signal fire

means A fire lit on high or visible ground to send a message—danger, arrival, or news—to people far away who are watching for it.

from Not a single coinage but an ancient, convergent practice — 'signal' traces back to Latin 'signum' meaning mark or sign, entering English through French around the medieval period to describe anything meant to convey information at a distance. The fires themselves are far older than the word: armies, coastal watches, and mountain chains of beacons used flame and smoke this way long before anyone called it 'signaling.' The most famous literary account comes from Aeschylus's 'Agamemnon,' where a chain of beacon fires carries news of Troy's fall across hundreds of miles in a single night — a relay system real ancient and medieval cultures actually used for war warnings and royal news.