jack-o’-lantern, in American holiday custom, a hollowed-out-pumpkin lantern that is displayed on Halloween.
The surface of the pumpkin is carved to resemble a face. Light from a candle inserted inside can be seen flickering through the jack-o’-lantern’s cutout eyes, nose, and usually grotesquely grinning mouth. The custom originated in the British Isles, with a large turnip or other vegetable rather than a pumpkin.