bulkhead

plural bulkheads

1. nauticalA vertical partition dividing the hull into separate compartments; often made watertight to prevent excessive flooding if the ship's hull is breached.

   Lastly, Lundberg went belowdecks to inspect the boat's bulkheads and hull—for what, it was not clear, since he had absolutely no knowledge of steamboat design.

   2003, Edward T. O'Donnell, Ship Ablaze: The Tragedy of the Steamboat General Slocum, page 54

2. aircraft; spacecraft; aircraft; spacecraftrail transportA similar partition in an aircraft or spacecraft, or some rail vehicles.

   Folding blinds are fitted to the cab bulkhead windows and sunblinds at the driving windows.

   1959 January 28, “Single-Unit Diesel Railcars for the Western Region”, in Railway Magazine, page 58

   1 more example

   For rigidity, two bulkheads are provided which are welded to the sides and underframe and which separate the cabs from the engine room.

   1958 September 28, “Swindon's First Main-Line Diesel Locomotive”, in Railway Magazine, page 601

3. engineeringA partition or panel through which connectors pass, or a connector designed to pass through a partition.
4. A pressure-resistant sealed barrier to any fluid in a large structure.
5. A retaining wall along a waterfront.
6. MaineRhode Island; Massachusetts; Rhode Island; MassachusettsA cellar hatchway.

   She bumped her noggin on the bulkhead above the doorway, smiled in apology for her presumed clumsiness.

   2003, John Farris, The Fury and the Power