nacelle vs railcar

nacelle

noun
  • The compartment that holds passengers on a hot-air balloon, a dirigible, or an aerostat; a gondola. 

  • A separate streamlined enclosure mounted on an aircraft to house an engine, cargo, or crew. 

  • The submersed providers of buoyancy of a SWATH hulled boat. 

  • The part between the tower and rotor of a wind turbine. 

railcar

noun
  • A self-propelled railway vehicle for passengers, similar to a bus. 

  • Any unpowered railway vehicle 

  • A powered single railway vehicle designed for passenger transport, with a driver's cab in both ends; Not to be confused with motor coach/motorcar, which is a powered railway vehicle capable to haul a train. 

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