floorboard vs mezzanine

floorboard

noun
  • Any of the long boards laid over joists to make a floor. 

  • The floor of a car. 

verb
  • To sink the gas pedal into the floorboard of the car, in order to bring the car to the highest possible speed. 

mezzanine

noun
  • An apartment, room, etc., on such an intermediate floor. 

  • An intermediate floor or storey in between the main floors of a building; specifically, one that is directly above the ground floor which does not extend over the whole floorspace of the building, and so resembles a large balcony overlooking the ground floor; an entresol. 

  • The lowest balcony in an auditorium, cinema, theatre, etc.; the dress circle. 

verb
  • To fit (a building or other place) with a mezzanine floor. 

adj
  • Characteristic of or relating to high-interest loans which have no collateral, and are regarded as intermediate in nature, ranking above equity but below secured loans. 

  • Fulfilling an intermediate or secondary function. 

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