couch vs futon

couch

noun
  • An item of furniture, often upholstered, for the comfortable seating of more than one person; a sofa. 

  • The den of an otter. 

  • A mass of steeped barley spread upon a floor to germinate, in malting; or the floor occupied by the barley. 

  • A preliminary layer, as of colour or size. 

  • Psychotherapy. 

  • Couch grass, a species of persistent grass, Elymus repens, usually considered a weed. 

  • A bed, a resting-place. 

verb
  • To attach a thread onto fabric with small stitches in order to add texture. 

  • To transfer (for example, sheets of partly dried pulp) from the wire mould to a felt blanket for further drying. 

  • To phrase in a particular style; to use specific wording for. 

  • To arrange or dispose as if in a bed. 

  • To bend the body, as in reverence, pain, labor, etc.; to stoop; to crouch. 

  • To lay something upon a bed or other resting place. 

  • To lay or deposit in a bed or layer; to bed. 

  • To lie down; to recline (upon a couch or other place of repose). 

  • To lower (a spear or lance) to the position of attack. 

  • In the treatment of a cataract in the eye, to displace the opaque lens with a sharp object such as a needle. The technique is regarded as largely obsolete. 

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. 

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