ceiling

noun

1. The overhead closure of a room.

   “The dining room had an ornate ceiling.”

2. 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.”

   “Market forces naturally move the economy to the equilibrium, and the price ceiling has no effect on the price or the quantity sold.”

3. The highest altitude at which an aircraft can safely maintain flight.
4. 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.”

5. 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.”

6. The inner planking of a vessel.
7. The maximum permitted level in a financial transaction.
8. The overhead interior surface that covers the upper limits of a room.

verb

1. (form-of, gerund, participle, present)present participle and gerund of ceil