waist cushion; cushion worn around the waist for warmth
A traditional padded cushion tied around the waist, used to keep the lower back and abdomen warm, especially in cold weather or for outdoor work.
In winter, my grandmother would wrap a waist cushion around herself while doing garden work.
Compound of 腰 (こし, 'waist, lower back') and 布団 (ふとん, 'cushion, futon').