hassock vs ottoman

hassock

noun
  • A thick cushion used as a seat; an ottoman or pouffe. 

  • A cushion used primarily in churches for kneeling on while praying. 

  • A dense clump of grass or vegetation; a tussock. 

ottoman

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

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

  • 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 hassock and ottoman occurred in a corpus of books? (source: Google Ngram Viewer )