winter retreat
Buddhist term for a period of intensive practice during winter, analogous to the summer retreat (夏安居).
See also: 夏安居
When the winter retreat begins at the Zen temple, the monks devote themselves to zazen without going outside.
From 冬 (winter) + 安居 (Buddhist retreat). The term 安居 derives from the Sanskrit vārṣika, originally referring to the rainy season retreat.