English

Noun

dead-light ‎(plural dead-lights)

1. A wooden cover of a ship's ports (window-openings), used to prevent water ingress in stormy weather, and to prevent glass windows breaking.
   • 1780, William Falconer, Dictionary of the Marine, page 411:

     DEAD-LIGHTS, certain wooden ports which are made to fasten into the cabin-windows, to prevent the waves from gushing into a ship in a high sea. As they are made exactly to fit the windows, and are strong enough to resist the waves, they are always fixed in, on the approach of a storm, and the glass frames taken out, which might otherwise be shattered to pieces by the surges, and suffer great quantities of water to enter the vessel.

   • 1850, Lydia Sigourney, The Happy Mariner from Poems for the Sea, page 100:

     Even, if our sails like ribbons fly, / And the dead-lights long are in, / Hard up the helm! and keep good heart! / Till skies are bright again.

2. A deck prism, a device to allow light into the cabin of boat through the deck.