earworm

The story

1. German · calque ofOhrwurm“tune that pops up in one’s memory all the time; earwig”
2. English todayearworm

From ear + worm; senses 1 and 3 (“tune that keeps replaying in one’s head”; “earwig”) are a calque of German Ohrwurm (“tune that pops up in one’s memory all the time; earwig”) (from the idea of a creature burrowing into the ear, an erroneous belief where earwigs are concerned), while sense 2 (“moth larva”) refers to the fact that these pests infest, among other things, ears of maize or sweet corn.