[ ded-lahyt ]

  1. a strong shutter able to be screwed against the interior of a porthole in heavy weather.

  2. a thick pane of glass set in the hull or deck to admit light.

Origin of deadlight

First recorded in 1720–30; dead + light1

Words Nearby deadlight Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use deadlight in a sentence

  • It was hot in the room, and rather dark, as the deadlight to the poop-deck was fogged by sea water.

    Isle o' Dreams | Frederick F. Moore
  • Then I flooded the boat rapidly through the deadlight till the water came to the level of the coaming.

    The Story of Our Submarines | John Graham Bower
  • Remembering his embarrassment of the morning, Denman did not seek the deck, but looked through his deadlight.

    The Wreck of the Titan | Morgan Robertson
  • Then he entered an opposite room—all were unlocked now—from which, slantingly through the deadlight, he saw lights.

    The Wreck of the Titan | Morgan Robertson
  • Foster remained, moodily staring through the deadlight, while the other two went forward.

    The Wreck of the Titan | Morgan Robertson

British Dictionary definitions for deadlight


/ (ˈdɛdˌlaɪt) /

  1. nautical

    • a bull's-eye let into the deck or hull of a vessel to admit light to a cabin

    • a shutter of wood or metal for sealing off a porthole or cabin window

  2. a skylight designed not to be opened

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012