futon vs trundle

futon

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

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

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

trundle

noun
  • A low bed on wheels that can be rolled underneath another bed. 

  • The sound made by an object being moved on wheels. 

  • A spool of golden thread. 

  • A lantern wheel, or one of its bars. 

  • A motion as of something moving upon little wheels or rollers; a rolling motion. 

verb
  • To move (something or someone), often heavily or clumsily. 

  • To transport (something or someone) using an object on wheels, especially one that is pushed. 

  • To roll or revolve; to roll along. 

  • To move heavily (on wheels). 

  • To cause (something) to roll or revolve; to roll (something) along. 

  • To wheel or roll (an object on wheels), especially by pushing, often slowly or heavily. 

  • To move, often heavily or clumsily. 

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