telegrafo

The device, not the message. This is the pair worth fixing: telegramo at 2,527 is the thing that arrives on a strip of paper, and telegrafo is the apparatus and the system that carry it. You do not receive a telegrafo and you do not install a telegramo. The verb telegrafi covers the act, so mi telegrafis al ŝi sends the message without naming either noun.

-grafo writes and -gramo is written. The two Greek pieces run right through the international vocabulary and they never swap jobs. Grafo from graphein is the writer or the recorder: telegrafo, fonografo, sismografo. Gramo from gramma is the thing recorded: telegramo, diagramo, programo. Once that is in place, an unfamiliar word ending in one of them tells you whether you are looking at a machine or at a page. Note that gramo the unit of weight is a separate root that only looks the same.

A dated word doing a modern job. Nobody sends telegrams any more, but telegrafo sits in every nineteenth-century text a learner will read, which is why it earns rank 2,948 in a corpus drawn from Esperanto's first fifty years. It is also the ancestor of the whole tele- family the language now leans on: telefono, televido, telekomunikado.