A lantern is an old-fashioned hand-held light, like the kind you might go looking for ghosts with. There are also modern ones — a lantern is any hand-held light with a see-through case. No ghosts necessary.
Some lanterns have an actual flame inside, but others are battery operated, like flashlights, but lanterns usually provide more light. There are also paper lanterns, which are fun for parties, and if you use a pumpkin you have yourself a jack o’ lantern. Lantern comes from the Latin lanterna, "lantern, lamp, or torch," and shares the Greek root lampein, "to shine," with the English word lamp.