noun (n)

• the overhead upper surface of a covered space(noun.artifact)

  Example:
  He hated painting the ceiling.
  

  source: wordnet30
• (meteorology) altitude of the lowest layer of clouds(noun.attribute)

  source: wordnet30
• an upper limit on what is allowed(noun.communication)

  Example:
  He put a ceiling on the number of women who worked for him.
  

  Synonym:
  cap, roof
  

  source: wordnet30
• maximum altitude at which a plane can fly (under specified conditions)(noun.attribute)

  source: wordnet30
• The inside lining of a room overhead; the under side of the floor above; the upper surface opposite to the floor.(noun)

  source: webster1913