The word earworm, which today describes infectious melodies that get stuck in your head, was first attested in 1598 in reference to the earwig insect, a usage that has since become archaic and is in fact unrelated to the modern meaning. That "catchy tune" definition comes from a 1978 calque of the German phrase Ohr wurm, also translating to "ear worm". The idea was that many pieces of music burrow into your head much like an insect would—an unpleasant thought, I know. Ohr comes from Old High German ora and Proto-Germanic auso, and ultimately traces to Proto-Indo-European hows, also meaning "ear". Wurm, meanwhile, is a relative of the English words worm and wyrm, and it comes from Middle High German wurm. Finally, that comes from Proto-Germanic wurmiz and Proto-Indo-European wrmis, which also meant "worm" and might be from wer, a verb meaning "to turn" or "bend".
Hello! I'm Adam Aleksic, a junior studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy trivia, politics, vexillology, geography, board games, conlanging, art history, and law.