futon

Futon comes from Japanese 布団 (futon), which was borrowed from Middle Chinese 蒲團 (bu dwan), meaning "meditation cushion." That term combined 蒲 (bu, "bulrush, cattail") and 團 (dwan, "sphere, round object"), describing a cushion woven from bulrushes into a round shape.

The original object was a round cushion made of woven bulrushes, used for sitting or meditating. The word traveled from Chinese into Japanese, where it came to describe a different kind of bedding altogether.

Mandarin still keeps a close cousin of this word in 蒲团 (pútuán), which likewise names a round meditation cushion.