1.
round straw cushion; circular seat cushion
A traditional round cushion, originally made of woven straw or rush, used for sitting on tatami floors. Also refers to modern circular cushions.
2.
sitting in a circle; forming a circle to sit together
The act of people sitting together in a circular arrangement, typically for conversation, drinking, or a meeting.
In modern usage, 円座 is also used for donut-shaped cushions (円座クッション) designed for comfort or medical purposes (e.g., hemorrhoid relief, postpartum recovery).