Jack-with-a-lantern , Jack-o'-lantern Meaning, Definition & Usage

Definitions
  1. . (a) An ignis fatuus; a will-o'-the-wisp . "[Newspaper speculations] supplying so many more jack-o'-lanterns to the future historian." Lowell. (b) A lantern made of a pumpkin so prepared as to show in illumination the features of a human face, etc.

Webster 1913