ceiling

noun8

1. •
   the part of a room above people's heads, opposite the floor

   • The dining room had an ornate ceiling.
2. •
   The overhead interior surface that covers the upper limits of a room.
3. •
   The upper limit of an object or action.

   • […] and only at Barnet did Tappin give Empire of India a burst to bring us up to the 60 m.p.h. speed ceiling of the London area. — 1956
4. •
   The highest altitude at which an aircraft can safely maintain flight.
5. •
   The maximum permitted level in a financial transaction.
6. •
   The smallest integer greater than or equal to a given number.

   • The ceiling of 4.5 is 5; the ceiling of −4.5 is −4.
7. •
   The measurement of visible distance from ground or sea level to an overcast cloud cover; under a clear sky, the ceiling measurement is identified as "unlimited."

   • Even though it was cloudy, there was still enough ceiling for the Blue Angels to perform a great show.
8. •
   The inner planking of a vessel.