air cushion vs throw pillow

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. 

throw pillow

noun

  • A small pillow, especially one placed on a chair or sofa rather than on a bed, used for decoration rather than comfort. 

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