in Architecture, the top or roof of a lower room; or a covering of plaster over laths nailed on the bottom of the joists that bear the floor of the upper room; or where there is no upper room, on joists for the purpose; hence called ceiling joists. The word ceiling answers pretty accurately to the Latin lacunar, "every thing over head."

Plastered ceilings are much used in Britain, more than any other country: nor are they without their advantages, as they make the room lightsome; are good in case of fire; stop the passage of the dust; lessen the noise over head; and, in summer, make the air cooler.

sea language, denotes the inside planks of a ship.