mattress vs throw pillow

mattress

noun
  • A pad on which a person can recline and sleep, usually having an inner section of coiled springs covered with foam or other cushioning material then enclosed with cloth fabric. 

  • A form of retaining wall used to support foundations or an embankment 

verb
  • To cover with a thick layer, like a mattress; to blanket. 

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 mattress and throw pillow occurred in a corpus of books? (source: Google Ngram Viewer )