ceiling vs downstairs

ceiling

noun
  • The overhead interior surface that covers the upper limits of a room. 

  • The highest altitude at which an aircraft can safely maintain flight. 

  • The smallest integer greater than or equal to a given number. 

  • The upper limit of an object or action. 

  • 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." 

  • The overhead closure of a room. 

  • The inner planking of a vessel. 

  • The maximum permitted level in a financial transaction. 

downstairs

noun
  • The lower floor of a house, at ground level; especially the servants’ quarters. 

  • The genitalia. 

adj
  • Located on a lower floor. 

adv
  • Down the stairs. 

  • In or to hell. 

  • Regarding the genitalia. 

How often have the words ceiling and downstairs occurred in a corpus of books? (source: Google Ngram Viewer )