noun
ceiling
SEE-ling/ˈsiːlɪŋ/
The upper interior surface of a room.
A small lamp hangs from the ceiling above the dining table.

Etymology
The root means hiding or covering: ceiling first named the act of paneling a room, then the paneling itself. Its meaning narrowed to the finished overhead surface.
In context
here's the ceiling which is a flat overhead extension and you look out from the interior through these side windows
More examples
- The attic room has a sloping ceiling.
- The policy sets a ceiling on annual spending.
- Their performance reaches the ceiling of the current equipment's capacity.
Forms
ceiling · ceilings