magneto

This is a place name that ate its own origin. Nothing in magneto means attract, or iron, or force. It means from Magnesia, a district of Thessaly where the ancient world quarried lodestone, and the Greek phrase was ho Magnes lithos, the Magnesian stone. The adjective outlived the noun it modified, travelled through Latin and French into every European language, and arrived in Esperanto still carrying a Greek postcode nobody notices. Two more minerals from the same neighbourhood went the same way: magnesium and manganese are the same word twice, once borrowed carefully and once garbled.

The family behind it is regular. Magneta is magnetic, magnetismo is magnetism, magnetigi is to magnetise something and magnetiĝi is to become magnetised - that -ig- and -iĝ- pair doing the work it always does. A compass is a kompaso or, more transparently, a magneta montrilo.

Not to be confused with magnato. One vowel apart: a magnato is a magnate, a person of great wealth and power, and the root is Latin magnus, great. The two words look related and are not. The rest of the magn- words in Esperanto - magnifika, magnitudo - belong to magnus as well, which leaves the magnet as the odd one out in a family it merely resembles.