futon vs love seat

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. 

love seat

noun
  • A small sofa for two people. 

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