downstairs vs entresol

downstairs

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

  • The genitalia. 

adv
  • Down the stairs. 

  • In or to hell. 

  • Regarding the genitalia. 

adj
  • Located on a lower floor. 

entresol

noun
  • A mezzanine; an intermediate floor in a building, typically resembling a balcony; most often, the floor immediately above the ground floor and below a higher floor. 

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