CEILING

n. overhead wall enclosing a room

v. finish a surface of a wall with plaster or thin boards; to furnish with a ceiling

A ceiling is an overhead interior surface that bounds the upper limit of a room. Generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above. A cathedral ceiling is any tall ceiling area similar to those in a church.A dropped ceiling is one in which the finished surface is constructed anywhere from a few inches to several feet below the structure above it. This may be done for aesthetic purposes, such as achieving a desirable ceiling height; or practical purposes such as providing a space for HVAC or piping. An inverse of this would be a raised floor.
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Noun
1. the overhead upper surface of a room; "he hated painting the ceiling"
(hypernym) upper surface
(hyponym) overhead
(part-holonym) room
2. (meteorology) altitude of the lowest layer of clouds
(hypernym) altitude, height
(classification) meteorology
3. an upper limit on what is allowed; "they established a cap for prices"
(synonym) cap
(hypernym) control
(hyponym) glass ceiling
4. maximum altitude at which a plane can fly (under specified conditions)
(hypernym) altitude, height
(hyponym) absolute ceiling

(v. t.)
The lining or finishing of any wall or other surface, with plaster, thin boards, etc.; also, the work when done.
  

(v. t.)
The inside lining of a room overhead; the under side of the floor above; the upper surface opposite to the floor.
  

(v. t.)
The inner planking of a vessel.
  

(p. pr. & vb. n.)
of Ceil
  

The highest price, interest rate, or other numerical factor allowable in a financial transaction.