Earworm eer-wurm] noun 1. A catchy song or tune that runs continually through a person's mindRipley awakes with an earworm in his head. It starts with the songs, but now, it's talking to him. "Call me Bogart," the voice informs him. "And we've got a lot of work to do." 2. An ancient parasite that uses humans as hostRipley and his earworm, Bogart, are now in a race against time to save his family from the murderous clutches of an ancient alien...