air cushion vs zabuton

air cushion

noun
  • A rubber or plastic inflatable cushion. 

  • A shock absorber that uses an air chamber. 

  • A layer of trapped air that supports a hovercraft. 

zabuton

noun
  • A Japanese cushion for sitting. 

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