Ceiling (noun)

1. The upper interior surface of a room or other similar space.
2. The highest level or limit of something, esp. prices or aspirations.

Origin:

Late middle english: from old french cieling, from ciel "sky" (from latin caelum).

Examples:

1. He was looking at the ceiling.
2. The ceiling was painted blue.
3. The ceiling of the cave was covered in stalactites.
4. The company had to lower its profit ceiling.
5. The government raised the ceiling for foreign investment.