futon vs ottoman

futon

noun
  • A specific kind of sofa-bed, with a fixed cushion that forms a mattress when folded down and a sofa when folded up. 

  • A round cushion used for Zen meditation, traditionally made of woven bulrush leaves. 

  • A thin mattress of tufted cotton or similar material, placed on a floor or on a raised, foldable frame as a bed. 

ottoman

noun
  • An upholstered sofa, without arms or a back, sometimes with a compartment for storing linen etc. 

  • A low stool or thick cushion used to rest the feet or as a seat. 

  • A fabric with a pronounced ribbed or corded effect, often made of silk or a mixture of cotton and silk-like yarns. 

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