means A 19th-century communication system that sent coded messages over long distances by electrical signals along wires, later by radio.

from Built from Greek 'tele' (far) and 'graphein' (to write) — literally 'far-writing.' The word predates the electric version: it first named visual signaling systems like the late-18th-century French semaphore towers, where operators waved mechanical arms to relay messages across the countryside. When electrical signaling arrived, it inherited the name, and 'telegram' followed for the messages themselves.