Most likely originated around the time of Hanson's "Mmmbop"; an ear worm refers to any song that is so catchy, and at the same time extremely annoying, that it feels like a worm has crawled into your ear and eaten the intelligent parts of your brain so that you hum the song all day long, no matter how much you hate it.
"I've had an ear worm for days since I heard the team team sing "100 bottles of beer on the wall" in the bus coming home from the game." Common ear worms:"The song that doesn't end," the theme from "Seseame Street" the bass rif from In-a-gadda-da-vida, the music from Mario and other video games, most commercials.Cure: Finding another less annoying song to replace it.