Jack-o'-lantern is a name often given to a hollowed-out pumpkin which has eyes, nose, and a mouth carved in one side. Jack-o'-lanterns are usually made on Halloween, and a candle or other light is placed inside the pumpkin. The term also refers to the light that frequently shines from rotting stumps or logs in swampy land. St. Elmo's fire is sometimes called jack-o'-lantern.