the.com/sofa bed

means A piece of furniture that folds out from a couch into a bed, built for small apartments and guests you like but not enough to give them a real room.

from Straightforward compound: 'sofa' arrived in English via French from Arabic 'suffa,' a raised, carpeted platform for sitting; 'bed' is an old Germanic word for a sleeping place. The object itself is a product of 20th-century furniture design, when fold-out mechanisms let a couch moonlight as a mattress — the name just describes exactly what it does, no folklore required.