A jack-o'-lantern is a pumpkin that's carved with a face and has a candle inside. If your neighbors celebrate Halloween enthusiastically, you'll see dozens of jack-o'-lanterns decorating their porches in late October.
To make a jack-o'lantern, you need a pumpkin with its insides scooped out and a sharp knife for carving eyes and a mouth. A lit candle inside will make the jack-o'-lantern's face glow in the dark. Jack-o'-lantern was originally a British name for a will-o'-the-wisp, a phenomenon involving glowing lights that hover over marshy areas at night. In early 1800s America, carved Halloween pumpkins took on the name.