A round, puffy cloth cap traditionally worn by elderly people and Buddhist monks. Often associated with historical or traditional settings.
See also: 大黒頭巾
Monks in the old days often wore a bouffant cloth cap.
I saw an old woman wearing a bouffant cloth cap in a period drama.
Compound of 丸 (round) and 頭巾 (hood/cap). The exact historical origin is uncertain, but the name describes its round, puffy shape.