deadlight

/ˈdɛdˌlaɪt/
noun
  1. A strong cover or shutter for a ship's porthole or window, used to keep out water during storms.
    • The crew fastened the deadlights before the storm hit.
    • He checked that all deadlights were securely closed before leaving port.
    • A deadlight protects the cabin from waves breaking against the hull.
  2. A window that does not open, especially in a building or vehicle.
    • In older houses, deadlights were common in stairwells.
    • The van's rear windows are deadlights for extra security.
    • The basement has a deadlight that lets in light but cannot be opened.
What does "deadlight" mean? | whatsthatwordmean | whatsthatwordmean