the.com/bean bag

means A fabric sack loosely filled with soft filler (originally dried beans or pellets, now usually foam beads) that molds to whatever shape sits, leans, or flops on it.

from Straightforward compound of 'bean' and 'bag' — small cloth sacks filled with dried beans were used for centuries as simple toys and tossing games. The idea scaled up in the 20th century when designers stuffed much bigger bags with foam pellets to make furniture that slumps and reshapes itself around a body instead of holding a fixed form — the name just rode along, even after actual beans left the recipe.