What is Lantern?

Lantern definition and meaning on Dictionary terms:
a transparent or translucent, usually portable, case for enclosing a light and protecting it from the wind, rain, etc.
the chamber at the top of a lighthouse, surrounding the light.
magic lantern.
Architecture. a tall, more or less open construction admitting light to an enclosed area below.any light, decorative structure of relatively small size crowning a roof, dome, open-sided structure on a roof to let out smoke or to assist ventilation.

a light, usually over the entrance to an elevator on each floor of a multistory building, that signals the approach of the elevator.