shutter

shutter
    n 1: a mechanical device on a camera that opens and closes to
         control the time of a photographic exposure
    2: a hinged blind for a window
    v 1: close with shutters; "We shuttered the window to keep the
         house cool"
    

Shutter \Shut"ter\, n.
   1. One who shuts or closes.
      [1913 Webster]

   2. A movable cover or screen for a window, designed to shut
      out the light, to obstruct the view, or to be of some
      strength as a defense; a blind.
      [1913 Webster]

   3. A removable cover, or a gate, for closing an aperture of
      any kind, as for closing the passageway for molten iron
      from a ladle.
      [1913 Webster]

   4. (Photog.) A mechanical device of various forms, attached
      to the aperture of a camera lens for opening and closing
      to expose the plate. It is usually designed so that the
      time during which the aperture is opened may be varied by
      a manual dial or by some automatic mechanism, thereby
      allowing proper exposure of a photographic film under
      different intensities of light.
      [Webster 1913 Suppl. +PJC]