Lan·tern n.
 1. Something inclosing a light, and protecting it from wind, rain, etc.; -- sometimes portable, as a closed vessel or case of horn, perforated tin, glass, oiled paper, or other material, having a lamp or candle within; sometimes fixed, as the glazed inclosure of a street light, or of a lighthouse light.
 2. Arch. (a) An open structure of light material set upon a roof, to give light and air to the interior. (b) A cage or open chamber of rich architecture, open below into the building or tower which it crowns. (c) A smaller and secondary cupola crowning a larger one, for ornament, or to admit light; such as the lantern of the cupola of the Capitol at Washington, or that of the Florence cathedral.
 3. Mach. A lantern pinion or trundle wheel. See Lantern pinion (below).
 4. Steam Engine A kind of cage inserted in a stuffing box and surrounding a piston rod, to separate the packing into two parts and form a chamber between for the reception of steam, etc.; -- called also lantern brass.
 5. Founding A perforated barrel to form a core upon.
 6. Zool. See Aristotle's lantern.
 Note: ☞ Fig. 1 represents a hand lantern; fig. 2, an arm lantern; fig. 3, a breast lantern; -- so named from the positions in which they are carried.
 Dark lantern, a lantern with a single opening, which may be closed so as to conceal the light; -- called also bull's-eye.
 Lantern jaws, long, thin jaws; hence, a thin visage.
 Lantern pinion, Lantern wheel Mach., a kind of pinion or wheel having cylindrical bars or trundles, instead of teeth, inserted at their ends in two parallel disks or plates; -- so called as resembling a lantern in shape; -- called also wallower, or trundle.
 Lantern shell Zool., any translucent, marine, bivalve shell of the genus Anatina, and allied genera.
 Magic lantern, an optical instrument consisting of a case inclosing a light, and having suitable lenses in a lateral tube, for throwing upon a screen, in a darkened room or the like, greatly magnified pictures from slides placed in the focus of the outer lens.